diff --git a/README.md b/README.md
index 15457d2..bb454b1 100644
--- a/README.md
+++ b/README.md
@@ -81,6 +81,7 @@ make it work with JUnit 5. Feel free to use the code (in package ```de.platon42.
 - New: Added Documentation Provider for symbol definitions (shows assigned declaration).
 - New: Added Documentation Provider for mnemonics (simple version, generated out of ISA information).
 - Bugfix: Macro definitions with colons and without space supported (as found in P61a source).
+- New: When asking for documentation on registers, a code flow analysis is done. Cool stuff!
 
 ### V0.3 (28-Jul-21)
 
diff --git a/build.gradle b/build.gradle
index fe4e251..eb6aabb 100644
--- a/build.gradle
+++ b/build.gradle
@@ -68,6 +68,7 @@ patchPluginXml {
       <li>New: Added Documentation Provider for symbol definitions (shows assigned declaration).
       <li>New: Added Documentation Provider for mnemonics (simple version, generated out of ISA information).
       <li>Bugfix: Macro definitions with colons and without space supported (as found in P61a source).
+      <li>New: When asking for documentation on registers, a code flow analysis is done. Cool stuff!
     </ul>
   <h4>V0.3 (28-Jul-21)</h4>
     <ul>
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/parser/M68kParser.java b/src/main/gen/de/platon42/intellij/plugins/m68k/parser/M68kParser.java
index a62496c..19f7344 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/parser/M68kParser.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/parser/M68kParser.java
@@ -211,7 +211,7 @@ public class M68kParser implements PsiParser, LightPsiParser {
     }
 
     /* ********************************************************** */
-    // ROUND_L (expr SEPARATOR)? AddressRegister SEPARATOR DataOrAddressRegister DataWidth? ROUND_R
+    // ROUND_L (expr SEPARATOR)? AddressRegister SEPARATOR IndexRegister ROUND_R
     public static boolean AddressRegisterIndirectWithIndexNewAddressingMode(PsiBuilder b, int l) {
         if (!recursion_guard_(b, l, "AddressRegisterIndirectWithIndexNewAddressingMode")) return false;
         if (!nextTokenIsFast(b, ROUND_L)) return false;
@@ -221,8 +221,7 @@ public class M68kParser implements PsiParser, LightPsiParser {
         r = r && AddressRegisterIndirectWithIndexNewAddressingMode_1(b, l + 1);
         r = r && AddressRegister(b, l + 1);
         r = r && consumeToken(b, SEPARATOR);
-        r = r && DataOrAddressRegister(b, l + 1);
-        r = r && AddressRegisterIndirectWithIndexNewAddressingMode_5(b, l + 1);
+        r = r && IndexRegister(b, l + 1);
         r = r && consumeToken(b, ROUND_R);
         exit_section_(b, l, m, r, false, null);
         return r;
@@ -246,15 +245,8 @@ public class M68kParser implements PsiParser, LightPsiParser {
         return r;
     }
 
-    // DataWidth?
-    private static boolean AddressRegisterIndirectWithIndexNewAddressingMode_5(PsiBuilder b, int l) {
-        if (!recursion_guard_(b, l, "AddressRegisterIndirectWithIndexNewAddressingMode_5")) return false;
-        DataWidth(b, l + 1);
-        return true;
-    }
-
     /* ********************************************************** */
-    // expr? ROUND_L AddressRegister SEPARATOR DataOrAddressRegister DataWidth? ROUND_R
+    // expr? ROUND_L AddressRegister SEPARATOR IndexRegister ROUND_R
     public static boolean AddressRegisterIndirectWithIndexOldAddressingMode(PsiBuilder b, int l) {
         if (!recursion_guard_(b, l, "AddressRegisterIndirectWithIndexOldAddressingMode")) return false;
         boolean r;
@@ -263,8 +255,7 @@ public class M68kParser implements PsiParser, LightPsiParser {
         r = r && consumeToken(b, ROUND_L);
         r = r && AddressRegister(b, l + 1);
         r = r && consumeToken(b, SEPARATOR);
-        r = r && DataOrAddressRegister(b, l + 1);
-        r = r && AddressRegisterIndirectWithIndexOldAddressingMode_5(b, l + 1);
+        r = r && IndexRegister(b, l + 1);
         r = r && consumeToken(b, ROUND_R);
         exit_section_(b, l, m, r, false, null);
         return r;
@@ -277,13 +268,6 @@ public class M68kParser implements PsiParser, LightPsiParser {
         return true;
     }
 
-    // DataWidth?
-    private static boolean AddressRegisterIndirectWithIndexOldAddressingMode_5(PsiBuilder b, int l) {
-        if (!recursion_guard_(b, l, "AddressRegisterIndirectWithIndexOldAddressingMode_5")) return false;
-        DataWidth(b, l + 1);
-        return true;
-    }
-
     /* ********************************************************** */
     // OPSIZE_W|OPSIZE_L
     public static boolean AddressSize(PsiBuilder b, int l) {
@@ -547,6 +531,25 @@ public class M68kParser implements PsiParser, LightPsiParser {
         return r;
     }
 
+    /* ********************************************************** */
+    // DataOrAddressRegister DataWidth?
+    public static boolean IndexRegister(PsiBuilder b, int l) {
+        if (!recursion_guard_(b, l, "IndexRegister")) return false;
+        boolean r;
+        Marker m = enter_section_(b, l, _NONE_, INDEX_REGISTER, "<index register>");
+        r = DataOrAddressRegister(b, l + 1);
+        r = r && IndexRegister_1(b, l + 1);
+        exit_section_(b, l, m, r, false, null);
+        return r;
+    }
+
+    // DataWidth?
+    private static boolean IndexRegister_1(PsiBuilder b, int l) {
+        if (!recursion_guard_(b, l, "IndexRegister_1")) return false;
+        DataWidth(b, l + 1);
+        return true;
+    }
+
     /* ********************************************************** */
     // AsmInstruction | MacroCall
     static boolean Instruction(PsiBuilder b, int l) {
@@ -938,7 +941,7 @@ public class M68kParser implements PsiParser, LightPsiParser {
     }
 
     /* ********************************************************** */
-    // ROUND_L (expr SEPARATOR)? PC SEPARATOR DataOrAddressRegister DataWidth? ROUND_R
+    // ROUND_L (expr SEPARATOR)? PC SEPARATOR IndexRegister ROUND_R
     public static boolean ProgramCounterIndirectWithIndexNewAddressingMode(PsiBuilder b, int l) {
         if (!recursion_guard_(b, l, "ProgramCounterIndirectWithIndexNewAddressingMode")) return false;
         if (!nextTokenIsFast(b, ROUND_L)) return false;
@@ -947,8 +950,7 @@ public class M68kParser implements PsiParser, LightPsiParser {
         r = consumeTokenFast(b, ROUND_L);
         r = r && ProgramCounterIndirectWithIndexNewAddressingMode_1(b, l + 1);
         r = r && consumeTokens(b, 0, PC, SEPARATOR);
-        r = r && DataOrAddressRegister(b, l + 1);
-        r = r && ProgramCounterIndirectWithIndexNewAddressingMode_5(b, l + 1);
+        r = r && IndexRegister(b, l + 1);
         r = r && consumeToken(b, ROUND_R);
         exit_section_(b, l, m, r, false, null);
         return r;
@@ -972,23 +974,15 @@ public class M68kParser implements PsiParser, LightPsiParser {
         return r;
     }
 
-    // DataWidth?
-    private static boolean ProgramCounterIndirectWithIndexNewAddressingMode_5(PsiBuilder b, int l) {
-        if (!recursion_guard_(b, l, "ProgramCounterIndirectWithIndexNewAddressingMode_5")) return false;
-        DataWidth(b, l + 1);
-        return true;
-    }
-
     /* ********************************************************** */
-    // expr? ROUND_L PC SEPARATOR DataOrAddressRegister DataWidth? ROUND_R
+    // expr? ROUND_L PC SEPARATOR IndexRegister ROUND_R
     public static boolean ProgramCounterIndirectWithIndexOldAddressingMode(PsiBuilder b, int l) {
         if (!recursion_guard_(b, l, "ProgramCounterIndirectWithIndexOldAddressingMode")) return false;
         boolean r;
         Marker m = enter_section_(b, l, _NONE_, PROGRAM_COUNTER_INDIRECT_WITH_INDEX_OLD_ADDRESSING_MODE, "<AddressingMode>");
         r = ProgramCounterIndirectWithIndexOldAddressingMode_0(b, l + 1);
         r = r && consumeTokens(b, 0, ROUND_L, PC, SEPARATOR);
-        r = r && DataOrAddressRegister(b, l + 1);
-        r = r && ProgramCounterIndirectWithIndexOldAddressingMode_5(b, l + 1);
+        r = r && IndexRegister(b, l + 1);
         r = r && consumeToken(b, ROUND_R);
         exit_section_(b, l, m, r, false, null);
         return r;
@@ -1001,13 +995,6 @@ public class M68kParser implements PsiParser, LightPsiParser {
         return true;
     }
 
-    // DataWidth?
-    private static boolean ProgramCounterIndirectWithIndexOldAddressingMode_5(PsiBuilder b, int l) {
-        if (!recursion_guard_(b, l, "ProgramCounterIndirectWithIndexOldAddressingMode_5")) return false;
-        DataWidth(b, l + 1);
-        return true;
-    }
-
     /* ********************************************************** */
     // CURRENT_PC_SYMBOL
     public static boolean ProgramCounterReference(PsiBuilder b, int l) {
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kAddressRegisterIndirectWithIndexNewAddressingMode.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kAddressRegisterIndirectWithIndexNewAddressingMode.java
index c2f542d..7fba59e 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kAddressRegisterIndirectWithIndexNewAddressingMode.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kAddressRegisterIndirectWithIndexNewAddressingMode.java
@@ -9,13 +9,10 @@ public interface M68kAddressRegisterIndirectWithIndexNewAddressingMode extends M
     @NotNull
     M68kAddressRegister getAddressRegister();
 
+    @NotNull
+    M68kIndexRegister getIndexRegister();
+
     @Nullable
     M68kExpr getDisplacement();
 
-    @NotNull
-    M68kRegister getIndexRegister();
-
-    @Nullable
-    M68kDataWidth getIndexWidth();
-
 }
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kAddressRegisterIndirectWithIndexOldAddressingMode.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kAddressRegisterIndirectWithIndexOldAddressingMode.java
index 9c47277..cdf1601 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kAddressRegisterIndirectWithIndexOldAddressingMode.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kAddressRegisterIndirectWithIndexOldAddressingMode.java
@@ -9,13 +9,10 @@ public interface M68kAddressRegisterIndirectWithIndexOldAddressingMode extends M
     @NotNull
     M68kAddressRegister getAddressRegister();
 
+    @NotNull
+    M68kIndexRegister getIndexRegister();
+
     @Nullable
     M68kExpr getDisplacement();
 
-    @NotNull
-    M68kRegister getIndexRegister();
-
-    @Nullable
-    M68kDataWidth getIndexWidth();
-
 }
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kIndexRegister.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kIndexRegister.java
new file mode 100644
index 0000000..edc267a
--- /dev/null
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kIndexRegister.java
@@ -0,0 +1,17 @@
+// This is a generated file. Not intended for manual editing.
+package de.platon42.intellij.plugins.m68k.psi;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public interface M68kIndexRegister extends M68kPsiElement {
+
+    @Nullable
+    M68kDataWidth getDataWidth();
+
+    @NotNull
+    M68kRegister getRegister();
+
+    boolean isLongWidth();
+
+}
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kProgramCounterIndirectWithIndexNewAddressingMode.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kProgramCounterIndirectWithIndexNewAddressingMode.java
index 0ad172d..c901c6f 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kProgramCounterIndirectWithIndexNewAddressingMode.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kProgramCounterIndirectWithIndexNewAddressingMode.java
@@ -6,13 +6,10 @@ import org.jetbrains.annotations.Nullable;
 
 public interface M68kProgramCounterIndirectWithIndexNewAddressingMode extends M68kAddressingMode, M68kWithDisplacement, M68kWithIndexRegister {
 
+    @NotNull
+    M68kIndexRegister getIndexRegister();
+
     @Nullable
     M68kExpr getDisplacement();
 
-    @NotNull
-    M68kRegister getIndexRegister();
-
-    @Nullable
-    M68kDataWidth getIndexWidth();
-
 }
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kProgramCounterIndirectWithIndexOldAddressingMode.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kProgramCounterIndirectWithIndexOldAddressingMode.java
index b78fd41..c9ec9e1 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kProgramCounterIndirectWithIndexOldAddressingMode.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kProgramCounterIndirectWithIndexOldAddressingMode.java
@@ -6,13 +6,10 @@ import org.jetbrains.annotations.Nullable;
 
 public interface M68kProgramCounterIndirectWithIndexOldAddressingMode extends M68kAddressingMode, M68kWithDisplacement, M68kWithIndexRegister {
 
+    @NotNull
+    M68kIndexRegister getIndexRegister();
+
     @Nullable
     M68kExpr getDisplacement();
 
-    @NotNull
-    M68kRegister getIndexRegister();
-
-    @Nullable
-    M68kDataWidth getIndexWidth();
-
 }
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kTypes.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kTypes.java
index 982ac09..1063464 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kTypes.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kTypes.java
@@ -48,6 +48,7 @@ public interface M68kTypes {
     IElementType EXPR = new M68kElementType("EXPR");
     IElementType GLOBAL_LABEL = M68kStubElementTypeFactory.stubFactory("GLOBAL_LABEL");
     IElementType IMMEDIATE_DATA = new M68kElementType("IMMEDIATE_DATA");
+    IElementType INDEX_REGISTER = new M68kElementType("INDEX_REGISTER");
     IElementType LITERAL_EXPR = new M68kElementType("LITERAL_EXPR");
     IElementType LOCAL_LABEL = new M68kElementType("LOCAL_LABEL");
     IElementType MACRO_CALL = new M68kElementType("MACRO_CALL");
@@ -212,6 +213,8 @@ public interface M68kTypes {
                 return new M68kGlobalLabelImpl(node);
             } else if (type == IMMEDIATE_DATA) {
                 return new M68kImmediateDataImpl(node);
+            } else if (type == INDEX_REGISTER) {
+                return new M68kIndexRegisterImpl(node);
             } else if (type == LITERAL_EXPR) {
                 return new M68kLiteralExprImpl(node);
             } else if (type == LOCAL_LABEL) {
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kVisitor.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kVisitor.java
index 098d9b3..09523ad 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kVisitor.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/M68kVisitor.java
@@ -99,6 +99,10 @@ public class M68kVisitor extends PsiElementVisitor {
         visitAddressingMode(o);
     }
 
+    public void visitIndexRegister(@NotNull M68kIndexRegister o) {
+        visitPsiElement(o);
+    }
+
     public void visitLocalLabel(@NotNull M68kLocalLabel o) {
         visitNamedElement(o);
     }
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kAddressRegisterIndirectWithIndexNewAddressingModeImpl.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kAddressRegisterIndirectWithIndexNewAddressingModeImpl.java
index da0d3a0..0ff5515 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kAddressRegisterIndirectWithIndexNewAddressingModeImpl.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kAddressRegisterIndirectWithIndexNewAddressingModeImpl.java
@@ -31,22 +31,16 @@ public class M68kAddressRegisterIndirectWithIndexNewAddressingModeImpl extends M
         return notNullChild(PsiTreeUtil.getChildOfType(this, M68kAddressRegister.class));
     }
 
+    @Override
+    @NotNull
+    public M68kIndexRegister getIndexRegister() {
+        return notNullChild(PsiTreeUtil.getChildOfType(this, M68kIndexRegister.class));
+    }
+
     @Override
     @Nullable
     public M68kExpr getDisplacement() {
         return PsiTreeUtil.getChildOfType(this, M68kExpr.class);
     }
 
-    @Override
-    @NotNull
-    public M68kRegister getIndexRegister() {
-        return notNullChild(PsiTreeUtil.getChildOfType(this, M68kRegister.class));
-    }
-
-    @Override
-    @Nullable
-    public M68kDataWidth getIndexWidth() {
-        return PsiTreeUtil.getChildOfType(this, M68kDataWidth.class);
-    }
-
 }
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kAddressRegisterIndirectWithIndexOldAddressingModeImpl.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kAddressRegisterIndirectWithIndexOldAddressingModeImpl.java
index 3cf6f4b..8321279 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kAddressRegisterIndirectWithIndexOldAddressingModeImpl.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kAddressRegisterIndirectWithIndexOldAddressingModeImpl.java
@@ -31,22 +31,16 @@ public class M68kAddressRegisterIndirectWithIndexOldAddressingModeImpl extends M
         return notNullChild(PsiTreeUtil.getChildOfType(this, M68kAddressRegister.class));
     }
 
+    @Override
+    @NotNull
+    public M68kIndexRegister getIndexRegister() {
+        return notNullChild(PsiTreeUtil.getChildOfType(this, M68kIndexRegister.class));
+    }
+
     @Override
     @Nullable
     public M68kExpr getDisplacement() {
         return PsiTreeUtil.getChildOfType(this, M68kExpr.class);
     }
 
-    @Override
-    @NotNull
-    public M68kRegister getIndexRegister() {
-        return notNullChild(PsiTreeUtil.getChildOfType(this, M68kRegister.class));
-    }
-
-    @Override
-    @Nullable
-    public M68kDataWidth getIndexWidth() {
-        return PsiTreeUtil.getChildOfType(this, M68kDataWidth.class);
-    }
-
 }
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kIndexRegisterImpl.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kIndexRegisterImpl.java
new file mode 100644
index 0000000..19e6d75
--- /dev/null
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kIndexRegisterImpl.java
@@ -0,0 +1,45 @@
+// This is a generated file. Not intended for manual editing.
+package de.platon42.intellij.plugins.m68k.psi.impl;
+
+import com.intellij.extapi.psi.ASTWrapperPsiElement;
+import com.intellij.lang.ASTNode;
+import com.intellij.psi.PsiElementVisitor;
+import com.intellij.psi.util.PsiTreeUtil;
+import de.platon42.intellij.plugins.m68k.psi.*;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class M68kIndexRegisterImpl extends ASTWrapperPsiElement implements M68kIndexRegister {
+
+    public M68kIndexRegisterImpl(@NotNull ASTNode node) {
+        super(node);
+    }
+
+    public void accept(@NotNull M68kVisitor visitor) {
+        visitor.visitIndexRegister(this);
+    }
+
+    @Override
+    public void accept(@NotNull PsiElementVisitor visitor) {
+        if (visitor instanceof M68kVisitor) accept((M68kVisitor) visitor);
+        else super.accept(visitor);
+    }
+
+    @Override
+    @Nullable
+    public M68kDataWidth getDataWidth() {
+        return PsiTreeUtil.getChildOfType(this, M68kDataWidth.class);
+    }
+
+    @Override
+    @NotNull
+    public M68kRegister getRegister() {
+        return notNullChild(PsiTreeUtil.getChildOfType(this, M68kRegister.class));
+    }
+
+    @Override
+    public boolean isLongWidth() {
+        return M68kPsiImplUtil.isLongWidth(this);
+    }
+
+}
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kProgramCounterIndirectWithIndexNewAddressingModeImpl.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kProgramCounterIndirectWithIndexNewAddressingModeImpl.java
index ea78fe5..8fb8ac1 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kProgramCounterIndirectWithIndexNewAddressingModeImpl.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kProgramCounterIndirectWithIndexNewAddressingModeImpl.java
@@ -4,7 +4,10 @@ package de.platon42.intellij.plugins.m68k.psi.impl;
 import com.intellij.lang.ASTNode;
 import com.intellij.psi.PsiElementVisitor;
 import com.intellij.psi.util.PsiTreeUtil;
-import de.platon42.intellij.plugins.m68k.psi.*;
+import de.platon42.intellij.plugins.m68k.psi.M68kExpr;
+import de.platon42.intellij.plugins.m68k.psi.M68kIndexRegister;
+import de.platon42.intellij.plugins.m68k.psi.M68kProgramCounterIndirectWithIndexNewAddressingMode;
+import de.platon42.intellij.plugins.m68k.psi.M68kVisitor;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -25,22 +28,16 @@ public class M68kProgramCounterIndirectWithIndexNewAddressingModeImpl extends M6
         else super.accept(visitor);
     }
 
+    @Override
+    @NotNull
+    public M68kIndexRegister getIndexRegister() {
+        return notNullChild(PsiTreeUtil.getChildOfType(this, M68kIndexRegister.class));
+    }
+
     @Override
     @Nullable
     public M68kExpr getDisplacement() {
         return PsiTreeUtil.getChildOfType(this, M68kExpr.class);
     }
 
-    @Override
-    @NotNull
-    public M68kRegister getIndexRegister() {
-        return notNullChild(PsiTreeUtil.getChildOfType(this, M68kRegister.class));
-    }
-
-    @Override
-    @Nullable
-    public M68kDataWidth getIndexWidth() {
-        return PsiTreeUtil.getChildOfType(this, M68kDataWidth.class);
-    }
-
 }
diff --git a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kProgramCounterIndirectWithIndexOldAddressingModeImpl.java b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kProgramCounterIndirectWithIndexOldAddressingModeImpl.java
index a8ef085..079eb83 100644
--- a/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kProgramCounterIndirectWithIndexOldAddressingModeImpl.java
+++ b/src/main/gen/de/platon42/intellij/plugins/m68k/psi/impl/M68kProgramCounterIndirectWithIndexOldAddressingModeImpl.java
@@ -4,7 +4,10 @@ package de.platon42.intellij.plugins.m68k.psi.impl;
 import com.intellij.lang.ASTNode;
 import com.intellij.psi.PsiElementVisitor;
 import com.intellij.psi.util.PsiTreeUtil;
-import de.platon42.intellij.plugins.m68k.psi.*;
+import de.platon42.intellij.plugins.m68k.psi.M68kExpr;
+import de.platon42.intellij.plugins.m68k.psi.M68kIndexRegister;
+import de.platon42.intellij.plugins.m68k.psi.M68kProgramCounterIndirectWithIndexOldAddressingMode;
+import de.platon42.intellij.plugins.m68k.psi.M68kVisitor;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -25,22 +28,16 @@ public class M68kProgramCounterIndirectWithIndexOldAddressingModeImpl extends M6
         else super.accept(visitor);
     }
 
+    @Override
+    @NotNull
+    public M68kIndexRegister getIndexRegister() {
+        return notNullChild(PsiTreeUtil.getChildOfType(this, M68kIndexRegister.class));
+    }
+
     @Override
     @Nullable
     public M68kExpr getDisplacement() {
         return PsiTreeUtil.getChildOfType(this, M68kExpr.class);
     }
 
-    @Override
-    @NotNull
-    public M68kRegister getIndexRegister() {
-        return notNullChild(PsiTreeUtil.getChildOfType(this, M68kRegister.class));
-    }
-
-    @Override
-    @Nullable
-    public M68kDataWidth getIndexWidth() {
-        return PsiTreeUtil.getChildOfType(this, M68kDataWidth.class);
-    }
-
 }
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/M68kFileElementType.kt b/src/main/java/de/platon42/intellij/plugins/m68k/M68kFileElementType.kt
index 9213532..721ef09 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/M68kFileElementType.kt
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/M68kFileElementType.kt
@@ -10,7 +10,7 @@ class M68kFileElementType private constructor() : ILightStubFileElementType<PsiF
         @JvmField
         val INSTANCE = M68kFileElementType()
 
-        const val STUB_VERSION = 4
+        const val STUB_VERSION = 5
         const val STUB_EXTERNAL_ID_PREFIX = "MC68000."
         const val EXTERNAL_ID = STUB_EXTERNAL_ID_PREFIX + "FILE"
     }
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/asm/M68kIsa.kt b/src/main/java/de/platon42/intellij/plugins/m68k/asm/M68kIsa.kt
index 92ea17d..f875fd0 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/asm/M68kIsa.kt
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/asm/M68kIsa.kt
@@ -28,7 +28,7 @@ enum class Register(val regname: String, val num: Int) {
     A7("a7", 7);
 
     companion object {
-        private val NAME_TO_REG_MAP = values().associateBy { it.regname }
+        private val NAME_TO_REG_MAP = values().associateBy { it.regname }.plus("sp" to A7)
 
         fun getRegFromName(regname: String) = NAME_TO_REG_MAP[regname.lowercase()]!!
     }
@@ -60,56 +60,58 @@ const val OP_SIZE_BWL = (OP_SIZE_B or OP_SIZE_W or OP_SIZE_L)
 const val OP_SIZE_WL = (OP_SIZE_W or OP_SIZE_L)
 const val OP_SIZE_SBW = (OP_SIZE_B or OP_SIZE_S or OP_SIZE_W)
 
-const val RWM_READ_OPSIZE = 0x10
-const val RWM_READ_B = 0x11
-const val RWM_READ_W = 0x12
-const val RWM_READ_L = 0x13
+const val RWM_OP_MASK = 0xfff
+const val RWM_SIZE_MASK = 0x00e
 
-const val RWM_SET_OPSIZE = 0x20
-const val RWM_SET_B = 0x21
-const val RWM_SET_W = 0x22
-const val RWM_SET_L = 0x23
+const val RWM_SET_OPSIZE = 0x008
+const val RWM_SET_B = 0x009
+const val RWM_SET_W = 0x00b
+const val RWM_SET_L = 0x00f
 
-const val RWM_MODIFY_OPSIZE = 0x30
-const val RWM_MODIFY_B = 0x31
-const val RWM_MODIFY_W = 0x32
-const val RWM_MODIFY_L = 0x33
+const val RWM_READ_OPSIZE = 0x800
+const val RWM_READ_B = 0x900
+const val RWM_READ_W = 0xb00
+const val RWM_READ_L = 0xf00
+
+const val RWM_MODIFY_OPSIZE = 0x880
+const val RWM_MODIFY_B = 0x990
+const val RWM_MODIFY_W = 0xbb0
+const val RWM_MODIFY_L = 0xff0
 
-const val RWM_OP_MASK = 0xff
 const val RWM_OP1_SHIFT = 0
-const val RWM_OP2_SHIFT = 8
+const val RWM_OP2_SHIFT = 12
 
 const val RWM_READ_OP1_OPSIZE = RWM_READ_OPSIZE shl RWM_OP1_SHIFT
 const val RWM_READ_OP1_B = RWM_READ_B shl RWM_OP1_SHIFT
 const val RWM_READ_OP1_W = RWM_READ_W shl RWM_OP1_SHIFT
 const val RWM_READ_OP1_L = RWM_READ_L shl RWM_OP1_SHIFT
 
-const val RWM_SET_OP1_OPSIZE = RWM_SET_OPSIZE shl RWM_OP1_SHIFT
-const val RWM_SET_OP1_B = RWM_SET_B shl RWM_OP1_SHIFT
-const val RWM_SET_OP1_W = RWM_SET_W shl RWM_OP1_SHIFT
-const val RWM_SET_OP1_L = RWM_SET_L shl RWM_OP1_SHIFT
-
 const val RWM_MODIFY_OP1_OPSIZE = RWM_MODIFY_OPSIZE shl RWM_OP1_SHIFT
 const val RWM_MODIFY_OP1_B = RWM_MODIFY_B shl RWM_OP1_SHIFT
 const val RWM_MODIFY_OP1_W = RWM_MODIFY_W shl RWM_OP1_SHIFT
 const val RWM_MODIFY_OP1_L = RWM_MODIFY_L shl RWM_OP1_SHIFT
 
+const val RWM_SET_OP1_OPSIZE = RWM_SET_OPSIZE shl RWM_OP1_SHIFT
+const val RWM_SET_OP1_B = RWM_SET_B shl RWM_OP1_SHIFT
+const val RWM_SET_OP1_W = RWM_SET_W shl RWM_OP1_SHIFT
+const val RWM_SET_OP1_L = RWM_SET_L shl RWM_OP1_SHIFT
+
 const val RWM_READ_OP2_OPSIZE = RWM_READ_OPSIZE shl RWM_OP2_SHIFT
 const val RWM_READ_OP2_B = RWM_READ_B shl RWM_OP2_SHIFT
 const val RWM_READ_OP2_W = RWM_READ_W shl RWM_OP2_SHIFT
 const val RWM_READ_OP2_L = RWM_READ_L shl RWM_OP2_SHIFT
 
-const val RWM_SET_OP2_OPSIZE = RWM_SET_OPSIZE shl RWM_OP2_SHIFT
-const val RWM_SET_OP2_B = RWM_SET_B shl RWM_OP2_SHIFT
-const val RWM_SET_OP2_W = RWM_SET_W shl RWM_OP2_SHIFT
-const val RWM_SET_OP2_L = RWM_SET_L shl RWM_OP2_SHIFT
-
 const val RWM_MODIFY_OP2_OPSIZE = RWM_MODIFY_OPSIZE shl RWM_OP2_SHIFT
 const val RWM_MODIFY_OP2_B = RWM_MODIFY_B shl RWM_OP2_SHIFT
 const val RWM_MODIFY_OP2_W = RWM_MODIFY_W shl RWM_OP2_SHIFT
 const val RWM_MODIFY_OP2_L = RWM_MODIFY_L shl RWM_OP2_SHIFT
 
-const val RWM_MODIFY_STACK = 0x10000
+const val RWM_SET_OP2_OPSIZE = RWM_SET_OPSIZE shl RWM_OP2_SHIFT
+const val RWM_SET_OP2_B = RWM_SET_B shl RWM_OP2_SHIFT
+const val RWM_SET_OP2_W = RWM_SET_W shl RWM_OP2_SHIFT
+const val RWM_SET_OP2_L = RWM_SET_L shl RWM_OP2_SHIFT
+
+const val RWM_MODIFY_STACK = 0x1000000
 
 data class AllowedAdrMode(
     val op1: Set<AddressMode>? = null,
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/documentation/M68kInstructionDocumentationProvider.kt b/src/main/java/de/platon42/intellij/plugins/m68k/documentation/M68kInstructionDocumentationProvider.kt
index be57905..98749f0 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/documentation/M68kInstructionDocumentationProvider.kt
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/documentation/M68kInstructionDocumentationProvider.kt
@@ -36,17 +36,17 @@ class M68kInstructionDocumentationProvider : AbstractDocumentationProvider() {
         val defBuilder = createDefinition(isaData)
         builder.append(defBuilder.wrapWith(DocumentationMarkup.DEFINITION_ELEMENT))
 
-        val bindingRows = HtmlBuilder()
+        val mnemonicInfoRows = HtmlBuilder()
         val headerCells = listOf(
             HtmlChunk.text("Mnemonic").wrapWith(DocumentationMarkup.SECTION_HEADER_CELL),
             HtmlChunk.text("Op1").wrapWith(DocumentationMarkup.SECTION_HEADER_CELL),
             HtmlChunk.text("Op2").wrapWith(DocumentationMarkup.SECTION_HEADER_CELL)
         )
-        bindingRows.append(HtmlChunk.tag("tr").children(headerCells))
+        mnemonicInfoRows.append(HtmlChunk.tag("tr").children(headerCells))
         isaData.modes.forEach { allowedAdrMode ->
             val mnemonics = findOpSizeDescriptions(allowedAdrMode.size)
-                .map { HtmlChunk.text(isaData.mnemonic + it).wrapWith(HtmlChunk.p()) }
-            bindingRows.append(
+                .map { HtmlChunk.text(isaData.mnemonic + it).wrapWith(HtmlChunk.div()) }
+            mnemonicInfoRows.append(
                 HtmlChunk.tag("tr").children(
                     DocumentationMarkup.SECTION_CONTENT_CELL.children(mnemonics),
                     DocumentationMarkup.SECTION_CONTENT_CELL.child(collectAddressModes(allowedAdrMode.op1)),
@@ -56,7 +56,7 @@ class M68kInstructionDocumentationProvider : AbstractDocumentationProvider() {
         }
 
         val contentBuilder = HtmlBuilder()
-        contentBuilder.append(bindingRows.br().wrapWith(DocumentationMarkup.SECTIONS_TABLE))
+        contentBuilder.append(mnemonicInfoRows.wrapWith(DocumentationMarkup.SECTIONS_TABLE))
 
         builder.append(contentBuilder.wrapWith(DocumentationMarkup.CONTENT_ELEMENT))
     }
@@ -77,7 +77,7 @@ class M68kInstructionDocumentationProvider : AbstractDocumentationProvider() {
         val defBuilder = HtmlBuilder()
         defBuilder.append(HtmlChunk.text(isaData.description).bold().wrapWith("pre"))
         if (isaData.isPrivileged) {
-            defBuilder.append(HtmlChunk.font("red").addText("(privileged)").wrapWith("p"))
+            defBuilder.append(HtmlChunk.font("red").addText("(privileged)").wrapWith(HtmlChunk.p()))
         }
         return defBuilder
     }
@@ -86,7 +86,7 @@ class M68kInstructionDocumentationProvider : AbstractDocumentationProvider() {
         if (addressModes == null) return HtmlChunk.text("")
         val modes = HtmlBuilder()
         addressModes.sortedBy(AddressMode::ordinal)
-            .forEach { modes.append(HtmlChunk.text(it.syntax).wrapWith(HtmlChunk.p())) }
+            .forEach { modes.append(HtmlChunk.text(it.syntax).wrapWith(HtmlChunk.div())) }
         return modes.toFragment()
     }
 
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/documentation/M68kRegisterFlowDocumentationProvider.kt b/src/main/java/de/platon42/intellij/plugins/m68k/documentation/M68kRegisterFlowDocumentationProvider.kt
index 62a4773..259ade8 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/documentation/M68kRegisterFlowDocumentationProvider.kt
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/documentation/M68kRegisterFlowDocumentationProvider.kt
@@ -1,34 +1,209 @@
 package de.platon42.intellij.plugins.m68k.documentation
 
 import com.intellij.lang.documentation.AbstractDocumentationProvider
+import com.intellij.lang.documentation.DocumentationMarkup
 import com.intellij.openapi.editor.Editor
+import com.intellij.openapi.util.text.HtmlBuilder
+import com.intellij.openapi.util.text.HtmlChunk
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
 import com.intellij.psi.util.PsiTreeUtil
-import de.platon42.intellij.plugins.m68k.asm.RWM_OP1_SHIFT
-import de.platon42.intellij.plugins.m68k.asm.RWM_OP2_SHIFT
+import de.platon42.intellij.plugins.m68k.asm.*
 import de.platon42.intellij.plugins.m68k.asm.Register.Companion.getRegFromName
-import de.platon42.intellij.plugins.m68k.psi.M68kAddressRegister
-import de.platon42.intellij.plugins.m68k.psi.M68kAddressingMode
-import de.platon42.intellij.plugins.m68k.psi.M68kAsmInstruction
-import de.platon42.intellij.plugins.m68k.psi.M68kDataRegister
+import de.platon42.intellij.plugins.m68k.psi.*
+import de.platon42.intellij.plugins.m68k.psi.M68kAddressModeUtil.getOtherReadWriteModifyRegisters
+import de.platon42.intellij.plugins.m68k.psi.M68kAddressModeUtil.getReadWriteModifyRegisters
 import de.platon42.intellij.plugins.m68k.utils.M68kIsaUtil.findExactIsaDataAndAllowedAdrModeForInstruction
+import de.platon42.intellij.plugins.m68k.utils.M68kIsaUtil.getOpSizeOrDefault
+import de.platon42.intellij.plugins.m68k.utils.M68kIsaUtil.modifyRwmWithOpsize
 
 class M68kRegisterFlowDocumentationProvider : AbstractDocumentationProvider() {
+
     override fun generateDoc(element: PsiElement, originalElement: PsiElement?): String? {
         if (element is M68kDataRegister || element is M68kAddressRegister) {
             val register = getRegFromName(element.text)
             val addressingMode = PsiTreeUtil.getParentOfType(element, M68kAddressingMode::class.java) ?: return null
             val asmInstruction = PsiTreeUtil.getParentOfType(addressingMode, M68kAsmInstruction::class.java) ?: return null
+
             val (isaData, adrMode) = findExactIsaDataAndAllowedAdrModeForInstruction(asmInstruction) ?: return "unknown instruction"
 
-            val opShift = if (asmInstruction.addressingModeList[0] == addressingMode) RWM_OP1_SHIFT else RWM_OP2_SHIFT
+            val cursorInstRwmRegs = evaluateRegisterUse(asmInstruction, adrMode, register)
+            val opSize = getOpSizeOrDefault(asmInstruction.asmOp.opSize, adrMode)
 
-            return register.regname
+            val rn = register.regname
+            val thisInfo = cursorInstRwmRegs
+                .joinToString(separator = ", ", prefix = "${isaData.mnemonic} instruction ") {
+                    rwmToDisplayText(it, rn)
+                }
+            val totalRwm = cursorInstRwmRegs.reduce(Int::or)
+
+            val firstOp = asmInstruction.addressingModeList[0] == addressingMode
+            val cursorRwm = modifyRwmWithOpsize((adrMode.modInfo ushr if (firstOp) RWM_OP1_SHIFT else RWM_OP2_SHIFT) and RWM_OP_MASK, opSize)
+            val analysisBuilder = HtmlBuilder()
+            val missingBits = if (cursorRwm and RWM_SET_L != 0) {
+                if (totalRwm and RWM_SET_L == RWM_SET_L) {
+                    analysisBuilder.append(HtmlChunk.text("Register result is fully defined by this instruction."))
+                    0
+                } else {
+                    (RWM_SET_L and RWM_SIZE_MASK) and totalRwm.inv()
+                }
+            } else {
+                (RWM_SET_L and RWM_SIZE_MASK) and ((cursorRwm and RWM_MODIFY_L) ushr 8)
+            }
+            val backtrace: MutableList<HtmlChunk> = ArrayList()
+            val initialStatement: M68kStatement = asmInstruction.parent as M68kStatement
+            if (missingBits > 0) {
+                val localLabelName = PsiTreeUtil.findChildOfType(initialStatement, M68kLocalLabel::class.java)?.name ?: ""
+                backtrace.add(
+                    HtmlChunk.tag("tr")
+                        .children(DocumentationMarkup.SECTION_CONTENT_CELL.child(HtmlChunk.text(localLabelName)))
+                        .children(highlightRegister(asmInstruction, register).bold().wrapWith(DocumentationMarkup.SECTION_CONTENT_CELL))
+                        .children(DocumentationMarkup.SECTION_CONTENT_CELL.child(HtmlChunk.text(" ; <--")))
+                )
+            }
+
+            backtrace.addAll(analyseFlow(register, missingBits, true, initialStatement) { PsiTreeUtil.getPrevSiblingOfType(it, M68kStatement::class.java) })
+            backtrace.reverse()
+            val traceBits = (cursorRwm or (cursorRwm ushr 8)) and RWM_SIZE_MASK
+            backtrace.addAll(analyseFlow(register, traceBits, false, initialStatement) { PsiTreeUtil.getNextSiblingOfType(it, M68kStatement::class.java) })
+
+            val statementRows = HtmlBuilder()
+            backtrace.forEach(statementRows::append)
+            val builder = HtmlBuilder()
+            builder.append(HtmlChunk.text(thisInfo).wrapWith(DocumentationMarkup.DEFINITION_ELEMENT))
+            builder.append(statementRows.wrapWith(DocumentationMarkup.SECTIONS_TABLE.style("padding-left: 8pt; padding-right: 8pt")))
+            builder.append(analysisBuilder.wrapWith(DocumentationMarkup.CONTENT_ELEMENT))
+            return builder.toString()
         }
         return null
     }
 
+    private fun analyseFlow(
+        register: Register,
+        rwmBits: Int,
+        globalLabelBreaksOnInitialStatement: Boolean,
+        startingStatement: M68kStatement,
+        direction: (statement: M68kStatement) -> M68kStatement?
+    ): MutableList<HtmlChunk> {
+        var missingBits = rwmBits
+        var currStatement = startingStatement
+        val backtrace: MutableList<HtmlChunk> = ArrayList()
+        val rn = register.regname
+        var addAbrevDots = false
+        while (missingBits > 0) {
+            val globalLabel = PsiTreeUtil.findChildOfType(currStatement, M68kGlobalLabel::class.java)
+            if ((globalLabel != null) && (globalLabelBreaksOnInitialStatement || (currStatement !== startingStatement))) {
+                backtrace.add(
+                    HtmlChunk.tag("tr")
+                        .children(DocumentationMarkup.SECTION_CONTENT_CELL.child(HtmlChunk.text(globalLabel.name!!).bold()))
+                        .children(DocumentationMarkup.SECTION_CONTENT_CELL.child(HtmlChunk.nbsp()))
+                        .children(DocumentationMarkup.SECTION_CONTENT_CELL.child(HtmlChunk.nbsp()))
+                )
+                break
+            }
+            currStatement = direction.invoke(currStatement) ?: break
+            val currAsmInstruction = PsiTreeUtil.getChildOfType(currStatement, M68kAsmInstruction::class.java) ?: continue
+            if (checkIfInstructionUsesRegister(currAsmInstruction, register)) {
+                if (addAbrevDots) {
+                    backtrace.add(
+                        HtmlChunk.tag("tr")
+                            .children(DocumentationMarkup.SECTION_CONTENT_CELL.child(HtmlChunk.nbsp()))
+                            .children(
+                                DocumentationMarkup.SECTION_CONTENT_CELL.child(
+                                    HtmlChunk.text("[...]").wrapWith(HtmlChunk.div().attr("class", "grayed"))
+                                )
+                            )
+                            .children(DocumentationMarkup.SECTION_CONTENT_CELL.child(HtmlChunk.nbsp()))
+                    )
+                }
+                addAbrevDots = false
+                val (_, currAdrMode) = findExactIsaDataAndAllowedAdrModeForInstruction(currAsmInstruction) ?: continue
+
+                val localLabelName = PsiTreeUtil.findChildOfType(currStatement, M68kLocalLabel::class.java)?.name ?: ""
+                val currRwms = evaluateRegisterUse(currAsmInstruction, currAdrMode, register)
+                val currTotalRwm = currRwms.reduce(Int::or)
+                if ((currTotalRwm and RWM_SET_L) > 0) {
+                    missingBits = missingBits and currTotalRwm.inv()
+                }
+                val lineInfo = currRwms
+                    .map {
+                        val text = HtmlChunk.text(rwmToDisplayText(it, rn))
+                        if ((missingBits and it) > 0) text.bold() else text.italic()
+                    }
+                val lineBuilder = HtmlBuilder()
+                lineBuilder.append(" ; ")
+                lineBuilder.appendWithSeparators(HtmlChunk.text(", "), lineInfo)
+                    .wrapWith(HtmlChunk.div())
+
+                backtrace.add(
+                    HtmlChunk.tag("tr")
+                        .children(DocumentationMarkup.SECTION_CONTENT_CELL.child(HtmlChunk.text(localLabelName)))
+                        .children(highlightRegister(currAsmInstruction, register).wrapWith(DocumentationMarkup.SECTION_CONTENT_CELL))
+                        .children(lineBuilder.wrapWith(DocumentationMarkup.SECTION_CONTENT_CELL))
+                )
+            } else {
+                addAbrevDots = true
+            }
+        }
+        return backtrace
+    }
+
+    private fun highlightRegister(currAsmInstruction: M68kAsmInstruction, register: Register): HtmlChunk {
+        val builder = HtmlBuilder()
+        val plainText = currAsmInstruction.text
+        var startPos = 0
+        val rn = if (register == Register.A7) listOf(register.regname, "sp") else listOf(register.regname)
+        do {
+            val indexPos = plainText.indexOfAny(rn, startPos, ignoreCase = true)
+            if (indexPos >= 0) {
+                builder.append(HtmlChunk.text(plainText.substring(startPos until indexPos)))
+                startPos = indexPos + register.regname.length
+                builder.append(HtmlChunk.text(plainText.substring(indexPos until startPos)).wrapWith(HtmlChunk.font("red")))
+            } else {
+                builder.append(HtmlChunk.text(plainText.substring(startPos)))
+            }
+        } while (indexPos >= 0)
+        return builder.toFragment().code()
+    }
+
+    private fun rwmToDisplayText(rwm: Int, rn: String) =
+        when (rwm) {
+            RWM_READ_B -> "reads $rn.b"
+            RWM_READ_W -> "reads $rn.w"
+            RWM_READ_L -> "reads $rn.l"
+            RWM_MODIFY_B -> "modifies $rn.b"
+            RWM_MODIFY_W -> "modifies $rn.w"
+            RWM_MODIFY_L -> "modifies $rn.l"
+            RWM_SET_B -> "sets $rn.b"
+            RWM_SET_W -> "sets $rn.w"
+            RWM_SET_L -> "sets $rn.l"
+            else -> "uhm?"
+        }
+
+    private fun evaluateRegisterUse(
+        asmInstruction: M68kAsmInstruction,
+        adrMode: AllowedAdrMode,
+        register: Register
+    ): List<Int> {
+        val opSize = getOpSizeOrDefault(asmInstruction.asmOp.opSize, adrMode)
+
+        val rwm1 = modifyRwmWithOpsize((adrMode.modInfo ushr RWM_OP1_SHIFT) and RWM_OP_MASK, opSize)
+        val rwm2 = if (asmInstruction.addressingModeList.size > 1) modifyRwmWithOpsize((adrMode.modInfo ushr RWM_OP2_SHIFT) and RWM_OP_MASK, opSize) else 0
+        return getReadWriteModifyRegisters(asmInstruction.addressingModeList[0], rwm1).asSequence()
+            .plus(getReadWriteModifyRegisters(asmInstruction.addressingModeList.getOrNull(1), rwm2))
+            .plus(getOtherReadWriteModifyRegisters(adrMode.modInfo))
+            .filter { it.first == register }
+            .map { it.second }
+            .toList()
+    }
+
+    private fun checkIfInstructionUsesRegister(instruction: M68kAsmInstruction, register: Register): Boolean {
+        if (instruction.addressingModeList.isEmpty()) {
+            return false
+        }
+        return instruction.addressingModeList.any { aml -> getReadWriteModifyRegisters(aml, 0).any { it.first == register } }
+    }
+
     override fun getCustomDocumentationElement(editor: Editor, file: PsiFile, contextElement: PsiElement?, targetOffset: Int): PsiElement? {
         if (contextElement == null) return null
         if (contextElement is M68kDataRegister || contextElement is M68kAddressRegister) return contextElement
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/m68k.bnf b/src/main/java/de/platon42/intellij/plugins/m68k/m68k.bnf
index a79352b..6241b2c 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/m68k.bnf
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/m68k.bnf
@@ -234,6 +234,14 @@ Register ::= DataRegister | AddressRegister | SpecialRegister
 
 private DataOrAddressRegister ::= DataRegister | AddressRegister { name = "data or address register"}
 
+IndexRegister ::= DataOrAddressRegister DataWidth?
+{
+    name = "index register"
+    methods = [
+        isLongWidth
+    ]
+}
+
 AddressingMode ::= ImmediateData
                 | AddressRegisterIndirectPreDecAddressingMode
                 | AddressRegisterIndirectPostIncAddressingMode
@@ -279,7 +287,7 @@ AddressRegisterIndirectWithDisplacementNewAddressingMode ::= ROUND_L expr SEPARA
     ]
 }
 
-AddressRegisterIndirectWithIndexOldAddressingMode ::= expr? ROUND_L AddressRegister SEPARATOR DataOrAddressRegister DataWidth? ROUND_R
+AddressRegisterIndirectWithIndexOldAddressingMode ::= expr? ROUND_L AddressRegister SEPARATOR IndexRegister ROUND_R
 {
     implements = [
         "de.platon42.intellij.plugins.m68k.psi.M68kWithAddressRegisterIndirect"
@@ -288,12 +296,10 @@ AddressRegisterIndirectWithIndexOldAddressingMode ::= expr? ROUND_L AddressRegis
     ]
     methods = [
         displacement = "expr"
-        indexRegister = "Register"
-        indexWidth = "DataWidth"
     ]
 }
 
-AddressRegisterIndirectWithIndexNewAddressingMode ::= ROUND_L (expr SEPARATOR)? AddressRegister SEPARATOR DataOrAddressRegister DataWidth? ROUND_R
+AddressRegisterIndirectWithIndexNewAddressingMode ::= ROUND_L (expr SEPARATOR)? AddressRegister SEPARATOR IndexRegister ROUND_R
 {
     implements = [
         "de.platon42.intellij.plugins.m68k.psi.M68kWithAddressRegisterIndirect"
@@ -302,8 +308,6 @@ AddressRegisterIndirectWithIndexNewAddressingMode ::= ROUND_L (expr SEPARATOR)?
     ]
     methods = [
         displacement = "expr"
-        indexRegister = "Register"
-        indexWidth = "DataWidth"
     ]
 }
 
@@ -323,7 +327,7 @@ ProgramCounterIndirectWithDisplacementNewAddressingMode ::= ROUND_L expr SEPARAT
     ]
 }
 
-ProgramCounterIndirectWithIndexOldAddressingMode ::= expr? ROUND_L PC SEPARATOR DataOrAddressRegister DataWidth? ROUND_R
+ProgramCounterIndirectWithIndexOldAddressingMode ::= expr? ROUND_L PC SEPARATOR IndexRegister ROUND_R
 {
     implements = [
         "de.platon42.intellij.plugins.m68k.psi.M68kWithDisplacement"
@@ -331,12 +335,10 @@ ProgramCounterIndirectWithIndexOldAddressingMode ::= expr? ROUND_L PC SEPARATOR
     ]
     methods = [
         displacement = "expr"
-        indexRegister = "Register"
-        indexWidth = "DataWidth"
     ]
 }
 
-ProgramCounterIndirectWithIndexNewAddressingMode ::= ROUND_L (expr SEPARATOR)? PC SEPARATOR DataOrAddressRegister DataWidth? ROUND_R
+ProgramCounterIndirectWithIndexNewAddressingMode ::= ROUND_L (expr SEPARATOR)? PC SEPARATOR IndexRegister ROUND_R
 {
     implements = [
         "de.platon42.intellij.plugins.m68k.psi.M68kWithDisplacement"
@@ -344,8 +346,6 @@ ProgramCounterIndirectWithIndexNewAddressingMode ::= ROUND_L (expr SEPARATOR)? P
     ]
     methods = [
         displacement = "expr"
-        indexRegister = "Register"
-        indexWidth = "DataWidth"
     ]
 }
 
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kAddressModeUtil.kt b/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kAddressModeUtil.kt
index 5ea485e..92e6d8e 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kAddressModeUtil.kt
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kAddressModeUtil.kt
@@ -27,31 +27,46 @@ object M68kAddressModeUtil {
         }
     }
 
-    fun getReadWriteModifyRegisters(addressingMode: M68kAddressingMode?, rwm: Int): Set<Pair<Register, Int>> {
-        if (addressingMode == null) return emptySet()
+    fun getOtherReadWriteModifyRegisters(rwm: Int): List<Pair<Register, Int>> {
+        if (rwm and RWM_MODIFY_STACK > 0) {
+            return listOf(Register.A7 to RWM_MODIFY_L)
+        }
+        return emptyList()
+    }
+
+    fun getReadWriteModifyRegisters(addressingMode: M68kAddressingMode?, rwm: Int): List<Pair<Register, Int>> {
+        if (addressingMode == null) return emptyList()
         return when (addressingMode) {
-            is M68kImmediateData -> emptySet()
-            is M68kAddressRegisterIndirectPostIncAddressingMode -> setOf(Register.getRegFromName(addressingMode.addressRegister.text) to RWM_MODIFY_OP1_L)
-            is M68kAddressRegisterIndirectPreDecAddressingMode -> setOf(Register.getRegFromName(addressingMode.addressRegister.text) to RWM_MODIFY_OP1_L)
+            is M68kImmediateData,
+            is M68kSpecialRegisterDirectAddressingMode,
+            is M68kProgramCounterIndirectWithDisplacementNewAddressingMode,
+            is M68kProgramCounterIndirectWithDisplacementOldAddressingMode,
+            is M68kAbsoluteAddressAddressingMode -> emptyList()
+
+            is M68kAddressRegisterIndirectPostIncAddressingMode -> listOf(Register.getRegFromName(addressingMode.addressRegister.text) to RWM_MODIFY_L)
+            is M68kAddressRegisterIndirectPreDecAddressingMode -> listOf(Register.getRegFromName(addressingMode.addressRegister.text) to RWM_MODIFY_L)
             is M68kWithAddressRegisterIndirect -> {
                 if (addressingMode is M68kWithIndexRegister) {
-                    setOf(
-                        Register.getRegFromName(addressingMode.addressRegister.text) to RWM_READ_OP1_L,
-                        Register.getRegFromName(addressingMode.indexRegister.text) to if (addressingMode.hasLongWidth()) RWM_READ_OP1_L else RWM_READ_OP1_W
+                    listOf(
+                        Register.getRegFromName(addressingMode.addressRegister.text) to RWM_READ_L,
+                        Register.getRegFromName(addressingMode.indexRegister.register.text) to if (addressingMode.indexRegister.isLongWidth) RWM_READ_L else RWM_READ_W
                     )
                 } else {
-                    setOf(Register.getRegFromName(addressingMode.addressRegister.text) to RWM_READ_OP1_L)
+                    listOf(Register.getRegFromName(addressingMode.addressRegister.text) to RWM_READ_L)
                 }
             }
-            is M68kWithIndexRegister -> setOf(Register.getRegFromName(addressingMode.indexRegister.text) to if (addressingMode.hasLongWidth()) RWM_READ_OP1_L else RWM_READ_OP1_W)
-            is M68kProgramCounterIndirectWithDisplacementNewAddressingMode -> emptySet()
-            is M68kProgramCounterIndirectWithDisplacementOldAddressingMode -> emptySet()
-            is M68kSpecialRegisterDirectAddressingMode -> emptySet()
-            is M68kDataRegisterDirectAddressingMode -> setOf(Register.getRegFromName(addressingMode.dataRegister.text) to rwm)
-            is M68kAddressRegisterDirectAddressingMode -> setOf(Register.getRegFromName(addressingMode.addressRegister.text) to rwm)
-            is M68kRegisterListAddressingMode -> addressingMode.registers.map { it to rwm }.toSet()
-            is M68kAbsoluteAddressAddressingMode -> emptySet()
+            is M68kWithIndexRegister -> listOf(Register.getRegFromName(addressingMode.indexRegister.register.text) to if (addressingMode.indexRegister.isLongWidth) RWM_READ_L else RWM_READ_W)
+            is M68kDataRegisterDirectAddressingMode -> listOf(Register.getRegFromName(addressingMode.dataRegister.text) to rwm)
+            is M68kAddressRegisterDirectAddressingMode -> listOf(Register.getRegFromName(addressingMode.addressRegister.text) to rwm)
+            is M68kRegisterListAddressingMode -> addressingMode.registers.map { it to rwm }
             else -> throw IllegalArgumentException("Unknown addressing mode $addressingMode")
         }
     }
+
+    fun mergeReadWriteModifyRegisters(regset: Set<Pair<Register, Int>>): Set<Pair<Register, Int>> {
+        if (regset.size <= 1) return regset
+        return regset.groupBy({ it.first }) { it.second }
+            .map { it.key to if (it.value.size == 1) it.value.single() else it.value.reduce(Int::or) }
+            .toSet()
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kPsiImplUtil.kt b/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kPsiImplUtil.kt
index f08ea9c..2325a89 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kPsiImplUtil.kt
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kPsiImplUtil.kt
@@ -134,4 +134,10 @@ object M68kPsiImplUtil {
         }
         return registers
     }
+
+    // IndexRegister
+    @JvmStatic
+    fun isLongWidth(element: M68kIndexRegister): Boolean {
+        return element.dataWidth?.text.equals(".l", ignoreCase = true)
+    }
 }
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithAddressRegisterIndirect.kt b/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithAddressRegisterIndirect.kt
index cde5e19..e3ec389 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithAddressRegisterIndirect.kt
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithAddressRegisterIndirect.kt
@@ -1,6 +1,6 @@
 package de.platon42.intellij.plugins.m68k.psi
 
-interface M68kWithAddressRegisterIndirect {
+interface M68kWithAddressRegisterIndirect : M68kAddressingMode {
 
     val addressRegister: M68kAddressRegister
 }
\ No newline at end of file
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithDisplacement.kt b/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithDisplacement.kt
index 3b8ace0..32556d8 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithDisplacement.kt
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithDisplacement.kt
@@ -1,6 +1,6 @@
 package de.platon42.intellij.plugins.m68k.psi
 
-interface M68kWithDisplacement {
+interface M68kWithDisplacement : M68kAddressingMode {
 
     val displacement: M68kExpr?
 }
\ No newline at end of file
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithIndexRegister.kt b/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithIndexRegister.kt
index 5c97c65..d862250 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithIndexRegister.kt
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/psi/M68kWithIndexRegister.kt
@@ -1,12 +1,6 @@
 package de.platon42.intellij.plugins.m68k.psi
 
-interface M68kWithIndexRegister {
+interface M68kWithIndexRegister : M68kAddressingMode {
 
-    val indexRegister: M68kRegister
-
-    val indexWidth: M68kDataWidth?
-
-    fun hasLongWidth(): Boolean {
-        return indexWidth?.text.equals(".l", ignoreCase = true)
-    }
+    val indexRegister: M68kIndexRegister
 }
\ No newline at end of file
diff --git a/src/main/java/de/platon42/intellij/plugins/m68k/utils/M68kIsaUtil.kt b/src/main/java/de/platon42/intellij/plugins/m68k/utils/M68kIsaUtil.kt
index dce2fc9..747e2a9 100644
--- a/src/main/java/de/platon42/intellij/plugins/m68k/utils/M68kIsaUtil.kt
+++ b/src/main/java/de/platon42/intellij/plugins/m68k/utils/M68kIsaUtil.kt
@@ -34,6 +34,42 @@ object M68kIsaUtil {
         return matchedIsaData.map { it to M68kIsa.findMatchingAddressMode(it.modes, op1, op2, opSize, specialReg) }
     }
 
+    fun getOpSizeOrDefault(opSize: Int, adrMode: AllowedAdrMode): Int {
+        if (opSize == OP_UNSIZED && (adrMode.size != OP_UNSIZED)) {
+            return if ((adrMode.size and OP_SIZE_W) == OP_SIZE_W) {
+                OP_SIZE_W
+            } else {
+                adrMode.size
+            }
+        }
+        return opSize
+    }
+
+    fun modifyRwmWithOpsize(rwm: Int, opSize: Int): Int {
+        if (opSize == OP_UNSIZED) return rwm
+        return when (rwm) {
+            RWM_READ_OPSIZE -> when (opSize) {
+                OP_SIZE_B -> RWM_READ_B
+                OP_SIZE_W -> RWM_READ_W
+                OP_SIZE_L -> RWM_READ_L
+                else -> rwm
+            }
+            RWM_MODIFY_OPSIZE -> when (opSize) {
+                OP_SIZE_B -> RWM_MODIFY_B
+                OP_SIZE_W -> RWM_MODIFY_W
+                OP_SIZE_L -> RWM_MODIFY_L
+                else -> rwm
+            }
+            RWM_SET_OPSIZE -> when (opSize) {
+                OP_SIZE_B -> RWM_SET_B
+                OP_SIZE_W -> RWM_SET_W
+                OP_SIZE_L -> RWM_SET_L
+                else -> rwm
+            }
+            else -> rwm
+        }
+    }
+
     fun findOpSizeDescription(opSize: Int): String {
         return when (opSize) {
             OP_UNSIZED -> ""
@@ -48,17 +84,17 @@ object M68kIsaUtil {
         }
     }
 
-    fun findOpSizeDescriptions(opSize: Int): Set<String> {
+    fun findOpSizeDescriptions(opSize: Int): List<String> {
         return when (opSize) {
-            OP_UNSIZED -> setOf("")
-            OP_SIZE_B -> setOf(".b")
-            OP_SIZE_W -> setOf(".w")
-            OP_SIZE_L -> setOf(".l")
-            OP_SIZE_S -> setOf(".s")
-            OP_SIZE_BWL -> setOf(".b", ".w", ".l")
-            OP_SIZE_WL -> setOf(".w", ".l")
-            OP_SIZE_SBW -> setOf(".s", ".b", ".w")
-            else -> setOf("?")
+            OP_UNSIZED -> listOf("")
+            OP_SIZE_B -> listOf(".b")
+            OP_SIZE_W -> listOf(".w")
+            OP_SIZE_L -> listOf(".l")
+            OP_SIZE_S -> listOf(".s")
+            OP_SIZE_BWL -> listOf(".b", ".w", ".l")
+            OP_SIZE_WL -> listOf(".w", ".l")
+            OP_SIZE_SBW -> listOf(".s", ".b", ".w")
+            else -> listOf("?")
         }
     }
 }
\ No newline at end of file
diff --git a/src/test/java/de/platon42/intellij/plugins/m68k/documentation/M68kInstructionDocumentationProviderTest.kt b/src/test/java/de/platon42/intellij/plugins/m68k/documentation/M68kInstructionDocumentationProviderTest.kt
index 23862f0..4e210f9 100644
--- a/src/test/java/de/platon42/intellij/plugins/m68k/documentation/M68kInstructionDocumentationProviderTest.kt
+++ b/src/test/java/de/platon42/intellij/plugins/m68k/documentation/M68kInstructionDocumentationProviderTest.kt
@@ -17,8 +17,10 @@ internal class M68kInstructionDocumentationProviderTest : AbstractDocumentationP
  mo<caret>veq.l #40,d0
         """
         )
-        assertThat(generateDocumentation(myFixture)).isEqualTo(
-            """<div class="definition"><pre><b>Move Quick</b></pre></div><div class="content"><table class="sections"><tr><td class="section" valign="top">Mnemonic</td><td class="section" valign="top">Op1</td><td class="section" valign="top">Op2</td></tr><tr><td valign="top"><p>moveq.l</p></td><td valign="top"><p>#&lt;xxx&gt;</p></td><td valign="top"><p>Dn</p></td></tr><br/></table></div>"""
+        assertThat(generateDocumentation(myFixture)).isEqualToIgnoringWhitespace(
+            """
+<div class="definition"><pre><b>Move Quick</b></pre></div><div class="content"><table class="sections"><tr><td class="section" valign="top">Mnemonic</td><td class="section" valign="top">Op1</td><td class="section" valign="top">Op2</td></tr><tr><td valign="top"><div>moveq.l</div></td><td valign="top"><div>#&lt;xxx&gt;</div></td><td valign="top"><div>Dn</div></td></tr></table></div>
+"""
         )
     }
 
@@ -29,8 +31,32 @@ internal class M68kInstructionDocumentationProviderTest : AbstractDocumentationP
  bra.<caret>s label
         """
         )
-        assertThat(generateDocumentation(myFixture)).isEqualTo(
-            """<div class="definition"><pre><b>Branch</b></pre></div><div class="content"><table class="sections"><tr><td class="section" valign="top">Mnemonic</td><td class="section" valign="top">Op1</td><td class="section" valign="top">Op2</td></tr><tr><td valign="top"><p>bra.s</p><p>bra.b</p><p>bra.w</p></td><td valign="top"><p>(xxx).w|l</p></td><td valign="top"></td></tr><br/></table></div>"""
+        assertThat(generateDocumentation(myFixture)).isEqualToIgnoringWhitespace(
+            """
+<div class="definition">
+    <pre><b>Branch</b></pre>
+</div>
+<div class="content">
+    <table class="sections">
+        <tr>
+            <td class="section" valign="top">Mnemonic</td>
+            <td class="section" valign="top">Op1</td>
+            <td class="section" valign="top">Op2</td>
+        </tr>
+        <tr>
+            <td valign="top">
+                <div>bra.s</div>
+                <div>bra.b</div>
+                <div>bra.w</div>
+            </td>
+            <td valign="top">
+                <div>(xxx).w|l</div>
+            </td>
+            <td valign="top"></td>
+        </tr>
+    </table>
+</div>
+            """
         )
     }
 
@@ -41,9 +67,7 @@ internal class M68kInstructionDocumentationProviderTest : AbstractDocumentationP
  <caret>reset
         """
         )
-        assertThat(generateDocumentation(myFixture)).isEqualTo(
-            """<div class="definition"><pre><b>Reset External Devices</b></pre><p><font color="red">(privileged)</font></p></div><div class="content"><table class="sections"><tr><td class="section" valign="top">Mnemonic</td><td class="section" valign="top">Op1</td><td class="section" valign="top">Op2</td></tr><tr><td valign="top"><p>reset</p></td><td valign="top"></td><td valign="top"></td></tr><br/></table></div>"""
-        )
+        assertThat(generateDocumentation(myFixture)).contains("Reset External Devices", "(privileged)")
     }
 
     @Test
diff --git a/src/test/java/de/platon42/intellij/plugins/m68k/documentation/M68kRegisterFlowDocumentationProviderTest.kt b/src/test/java/de/platon42/intellij/plugins/m68k/documentation/M68kRegisterFlowDocumentationProviderTest.kt
index 7350677..1eab5f5 100644
--- a/src/test/java/de/platon42/intellij/plugins/m68k/documentation/M68kRegisterFlowDocumentationProviderTest.kt
+++ b/src/test/java/de/platon42/intellij/plugins/m68k/documentation/M68kRegisterFlowDocumentationProviderTest.kt
@@ -11,21 +11,93 @@ import org.junit.jupiter.api.extension.ExtendWith
 internal class M68kRegisterFlowDocumentationProviderTest : AbstractDocumentationProviderTest() {
 
     @Test
-    internal fun check_documentation_for_a_symbol_definition(@MyFixture myFixture: CodeInsightTestFixture) {
+    internal fun check_documentation_for_a_register_in_code_flow(@MyFixture myFixture: CodeInsightTestFixture) {
         myFixture.configureByText(
             "documentme.asm", """
 label
     moveq.l #0,d0
     add.w   #1,d0
+    move.l  d1,-(sp)
     move.w  d0,d1
     move.b  d2,d0
     addq.b  #1,d0
     move.w  d<caret>0,d1
     move.l  d0,d2
     move.w  d1,d2
+    clr.b   d0
+    moveq.l #0,d0
+    move.l  (sp)+,d1
     rts
+nextlabel
         """
         )
-        assertThat(generateDocumentation(myFixture)).isEqualTo("d0")
+        assertThat(generateDocumentation(myFixture))
+            .isEqualToIgnoringWhitespace(
+                """
+<div class="definition">move instruction reads d0.w</div>
+<table class="sections" style="padding-left: 8pt; padding-right: 8pt">
+    <tr>
+        <td valign="top"></td>
+        <td valign="top"><code>moveq.l #0,<font color="red">d0</font></code></td>
+        <td valign="top"> ; <i>sets d0.l</i></td>
+    </tr>
+    <tr>
+        <td valign="top"></td>
+        <td valign="top"><code>add.w #1,<font color="red">d0</font></code></td>
+        <td valign="top"> ; <i>modifies d0.w</i></td>
+    </tr>
+    <tr>
+        <td valign="top">&nbsp;</td>
+        <td valign="top">
+            <div class="grayed">[...]</div>
+        </td>
+        <td valign="top">&nbsp;</td>
+    </tr>
+    <tr>
+        <td valign="top"></td>
+        <td valign="top"><code>move.w <font color="red">d0</font>,d1</code></td>
+        <td valign="top"> ; <i>reads d0.w</i></td>
+    </tr>
+    <tr>
+        <td valign="top"></td>
+        <td valign="top"><code>move.b d2,<font color="red">d0</font></code></td>
+        <td valign="top"> ; <i>sets d0.b</i></td>
+    </tr>
+    <tr>
+        <td valign="top"></td>
+        <td valign="top"><code>addq.b #1,<font color="red">d0</font></code></td>
+        <td valign="top"> ; <i>modifies d0.b</i></td>
+    </tr>
+    <tr>
+        <td valign="top"></td>
+        <td valign="top"><b><code>move.w <font color="red">d0</font>,d1</code></b></td>
+        <td valign="top"> ; &lt;--</td>
+    </tr>
+    <tr>
+        <td valign="top"></td>
+        <td valign="top"><code>move.l <font color="red">d0</font>,d2</code></td>
+        <td valign="top"> ; <i>reads d0.l</i></td>
+    </tr>
+    <tr>
+        <td valign="top">&nbsp;</td>
+        <td valign="top">
+            <div class="grayed">[...]</div>
+        </td>
+        <td valign="top">&nbsp;</td>
+    </tr>
+    <tr>
+        <td valign="top"></td>
+        <td valign="top"><code>clr.b <font color="red">d0</font></code></td>
+        <td valign="top"> ; <i>sets d0.b</i></td>
+    </tr>
+    <tr>
+        <td valign="top"></td>
+        <td valign="top"><code>moveq.l #0,<font color="red">d0</font></code></td>
+        <td valign="top"> ; <i>sets d0.l</i></td>
+    </tr>
+</table>
+<div class="content"/>
+            """.trimIndent()
+            )
     }
 }
\ No newline at end of file
diff --git a/src/test/resources/parser/addressingmodes/complex_math_expression_in_displacement.txt b/src/test/resources/parser/addressingmodes/complex_math_expression_in_displacement.txt
index ce27e5f..3d4380b 100644
--- a/src/test/resources/parser/addressingmodes/complex_math_expression_in_displacement.txt
+++ b/src/test/resources/parser/addressingmodes/complex_math_expression_in_displacement.txt
@@ -177,9 +177,10 @@ Assembly File: a.asm
         M68kAddressRegisterImpl(ADDRESS_REGISTER)
           PsiElement(M68kTokenType.AREG)('a0')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kDataRegisterImpl(DATA_REGISTER)
-          PsiElement(M68kTokenType.DREG)('d0')
-        M68kDataWidthImpl(DATA_WIDTH)
-          PsiElement(M68kTokenType.OPSIZE_L)('.l')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kDataRegisterImpl(DATA_REGISTER)
+            PsiElement(M68kTokenType.DREG)('d0')
+          M68kDataWidthImpl(DATA_WIDTH)
+            PsiElement(M68kTokenType.OPSIZE_L)('.l')
         PsiElement(M68kTokenType.ROUND_R)(')')
   PsiElement(M68kTokenType.EOL)('\n')
\ No newline at end of file
diff --git a/src/test/resources/parser/addressingmodes/pc_indirect_with_index_and_offset_new_syntax.txt b/src/test/resources/parser/addressingmodes/pc_indirect_with_index_and_offset_new_syntax.txt
index 84d08aa..d46fbb7 100644
--- a/src/test/resources/parser/addressingmodes/pc_indirect_with_index_and_offset_new_syntax.txt
+++ b/src/test/resources/parser/addressingmodes/pc_indirect_with_index_and_offset_new_syntax.txt
@@ -21,8 +21,9 @@ Assembly File: a.asm
         PsiElement(M68kTokenType.SEPARATOR)(',')
         PsiElement(M68kTokenType.PC)('pc')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kAddressRegisterImpl(ADDRESS_REGISTER)
-          PsiElement(M68kTokenType.AREG)('a0')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kAddressRegisterImpl(ADDRESS_REGISTER)
+            PsiElement(M68kTokenType.AREG)('a0')
         PsiElement(M68kTokenType.ROUND_R)(')')
       PsiElement(M68kTokenType.SEPARATOR)(',')
       M68kProgramCounterIndirectWithIndexNewAddressingModeImpl(PROGRAM_COUNTER_INDIRECT_WITH_INDEX_NEW_ADDRESSING_MODE)
@@ -43,9 +44,10 @@ Assembly File: a.asm
         PsiElement(M68kTokenType.SEPARATOR)(',')
         PsiElement(M68kTokenType.PC)('pc')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kDataRegisterImpl(DATA_REGISTER)
-          PsiElement(M68kTokenType.DREG)('d5')
-        M68kDataWidthImpl(DATA_WIDTH)
-          PsiElement(M68kTokenType.OPSIZE_L)('.l')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kDataRegisterImpl(DATA_REGISTER)
+            PsiElement(M68kTokenType.DREG)('d5')
+          M68kDataWidthImpl(DATA_WIDTH)
+            PsiElement(M68kTokenType.OPSIZE_L)('.l')
         PsiElement(M68kTokenType.ROUND_R)(')')
   PsiElement(M68kTokenType.EOL)('\n')
\ No newline at end of file
diff --git a/src/test/resources/parser/addressingmodes/pc_indirect_with_index_and_offset_old_syntax.txt b/src/test/resources/parser/addressingmodes/pc_indirect_with_index_and_offset_old_syntax.txt
index bda3476..1faca7c 100644
--- a/src/test/resources/parser/addressingmodes/pc_indirect_with_index_and_offset_old_syntax.txt
+++ b/src/test/resources/parser/addressingmodes/pc_indirect_with_index_and_offset_old_syntax.txt
@@ -20,10 +20,11 @@ Assembly File: a.asm
         PsiElement(M68kTokenType.ROUND_L)('(')
         PsiElement(M68kTokenType.PC)('pc')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kDataRegisterImpl(DATA_REGISTER)
-          PsiElement(M68kTokenType.DREG)('d0')
-        M68kDataWidthImpl(DATA_WIDTH)
-          PsiElement(M68kTokenType.OPSIZE_W)('.w')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kDataRegisterImpl(DATA_REGISTER)
+            PsiElement(M68kTokenType.DREG)('d0')
+          M68kDataWidthImpl(DATA_WIDTH)
+            PsiElement(M68kTokenType.OPSIZE_W)('.w')
         PsiElement(M68kTokenType.ROUND_R)(')')
       PsiElement(M68kTokenType.SEPARATOR)(',')
       M68kProgramCounterIndirectWithIndexOldAddressingModeImpl(PROGRAM_COUNTER_INDIRECT_WITH_INDEX_OLD_ADDRESSING_MODE)
@@ -43,7 +44,8 @@ Assembly File: a.asm
         PsiElement(M68kTokenType.ROUND_L)('(')
         PsiElement(M68kTokenType.PC)('pc')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kAddressRegisterImpl(ADDRESS_REGISTER)
-          PsiElement(M68kTokenType.AREG)('a3')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kAddressRegisterImpl(ADDRESS_REGISTER)
+            PsiElement(M68kTokenType.AREG)('a3')
         PsiElement(M68kTokenType.ROUND_R)(')')
   PsiElement(M68kTokenType.EOL)('\n')
\ No newline at end of file
diff --git a/src/test/resources/parser/addressingmodes/pc_indirect_with_index_special_case_without_offset.txt b/src/test/resources/parser/addressingmodes/pc_indirect_with_index_special_case_without_offset.txt
index 096dfe3..a2ffbda 100644
--- a/src/test/resources/parser/addressingmodes/pc_indirect_with_index_special_case_without_offset.txt
+++ b/src/test/resources/parser/addressingmodes/pc_indirect_with_index_special_case_without_offset.txt
@@ -11,17 +11,19 @@ Assembly File: a.asm
         PsiElement(M68kTokenType.ROUND_L)('(')
         PsiElement(M68kTokenType.PC)('pc')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kDataRegisterImpl(DATA_REGISTER)
-          PsiElement(M68kTokenType.DREG)('d0')
-        M68kDataWidthImpl(DATA_WIDTH)
-          PsiElement(M68kTokenType.OPSIZE_W)('.w')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kDataRegisterImpl(DATA_REGISTER)
+            PsiElement(M68kTokenType.DREG)('d0')
+          M68kDataWidthImpl(DATA_WIDTH)
+            PsiElement(M68kTokenType.OPSIZE_W)('.w')
         PsiElement(M68kTokenType.ROUND_R)(')')
       PsiElement(M68kTokenType.SEPARATOR)(',')
       M68kProgramCounterIndirectWithIndexNewAddressingModeImpl(PROGRAM_COUNTER_INDIRECT_WITH_INDEX_NEW_ADDRESSING_MODE)
         PsiElement(M68kTokenType.ROUND_L)('(')
         PsiElement(M68kTokenType.PC)('pc')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kAddressRegisterImpl(ADDRESS_REGISTER)
-          PsiElement(M68kTokenType.AREG)('a3')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kAddressRegisterImpl(ADDRESS_REGISTER)
+            PsiElement(M68kTokenType.AREG)('a3')
         PsiElement(M68kTokenType.ROUND_R)(')')
   PsiElement(M68kTokenType.EOL)('\n')
\ No newline at end of file
diff --git a/src/test/resources/parser/addressingmodes/register_indirect_with_index_and_offset_new_syntax.txt b/src/test/resources/parser/addressingmodes/register_indirect_with_index_and_offset_new_syntax.txt
index dddf1f8..64c9171 100644
--- a/src/test/resources/parser/addressingmodes/register_indirect_with_index_and_offset_new_syntax.txt
+++ b/src/test/resources/parser/addressingmodes/register_indirect_with_index_and_offset_new_syntax.txt
@@ -22,8 +22,9 @@ Assembly File: a.asm
         M68kAddressRegisterImpl(ADDRESS_REGISTER)
           PsiElement(M68kTokenType.REG_SP)('sp')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kAddressRegisterImpl(ADDRESS_REGISTER)
-          PsiElement(M68kTokenType.AREG)('a0')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kAddressRegisterImpl(ADDRESS_REGISTER)
+            PsiElement(M68kTokenType.AREG)('a0')
         PsiElement(M68kTokenType.ROUND_R)(')')
       PsiElement(M68kTokenType.SEPARATOR)(',')
       M68kAddressRegisterIndirectWithIndexNewAddressingModeImpl(ADDRESS_REGISTER_INDIRECT_WITH_INDEX_NEW_ADDRESSING_MODE)
@@ -45,9 +46,10 @@ Assembly File: a.asm
         M68kAddressRegisterImpl(ADDRESS_REGISTER)
           PsiElement(M68kTokenType.AREG)('a1')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kDataRegisterImpl(DATA_REGISTER)
-          PsiElement(M68kTokenType.DREG)('d5')
-        M68kDataWidthImpl(DATA_WIDTH)
-          PsiElement(M68kTokenType.OPSIZE_L)('.l')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kDataRegisterImpl(DATA_REGISTER)
+            PsiElement(M68kTokenType.DREG)('d5')
+          M68kDataWidthImpl(DATA_WIDTH)
+            PsiElement(M68kTokenType.OPSIZE_L)('.l')
         PsiElement(M68kTokenType.ROUND_R)(')')
   PsiElement(M68kTokenType.EOL)('\n')
\ No newline at end of file
diff --git a/src/test/resources/parser/addressingmodes/register_indirect_with_index_and_offset_old_syntax.txt b/src/test/resources/parser/addressingmodes/register_indirect_with_index_and_offset_old_syntax.txt
index a5f4069..dc25b97 100644
--- a/src/test/resources/parser/addressingmodes/register_indirect_with_index_and_offset_old_syntax.txt
+++ b/src/test/resources/parser/addressingmodes/register_indirect_with_index_and_offset_old_syntax.txt
@@ -21,10 +21,11 @@ Assembly File: a.asm
         M68kAddressRegisterImpl(ADDRESS_REGISTER)
           PsiElement(M68kTokenType.REG_SP)('sp')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kDataRegisterImpl(DATA_REGISTER)
-          PsiElement(M68kTokenType.DREG)('d0')
-        M68kDataWidthImpl(DATA_WIDTH)
-          PsiElement(M68kTokenType.OPSIZE_W)('.w')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kDataRegisterImpl(DATA_REGISTER)
+            PsiElement(M68kTokenType.DREG)('d0')
+          M68kDataWidthImpl(DATA_WIDTH)
+            PsiElement(M68kTokenType.OPSIZE_W)('.w')
         PsiElement(M68kTokenType.ROUND_R)(')')
       PsiElement(M68kTokenType.SEPARATOR)(',')
       M68kAddressRegisterIndirectWithIndexOldAddressingModeImpl(ADDRESS_REGISTER_INDIRECT_WITH_INDEX_OLD_ADDRESSING_MODE)
@@ -45,7 +46,8 @@ Assembly File: a.asm
         M68kAddressRegisterImpl(ADDRESS_REGISTER)
           PsiElement(M68kTokenType.AREG)('a1')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kAddressRegisterImpl(ADDRESS_REGISTER)
-          PsiElement(M68kTokenType.AREG)('a3')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kAddressRegisterImpl(ADDRESS_REGISTER)
+            PsiElement(M68kTokenType.AREG)('a3')
         PsiElement(M68kTokenType.ROUND_R)(')')
   PsiElement(M68kTokenType.EOL)('\n')
\ No newline at end of file
diff --git a/src/test/resources/parser/addressingmodes/register_indirect_with_index_special_case_without_offset.txt b/src/test/resources/parser/addressingmodes/register_indirect_with_index_special_case_without_offset.txt
index 9c0c73d..24dc72b 100644
--- a/src/test/resources/parser/addressingmodes/register_indirect_with_index_special_case_without_offset.txt
+++ b/src/test/resources/parser/addressingmodes/register_indirect_with_index_special_case_without_offset.txt
@@ -12,10 +12,11 @@ Assembly File: a.asm
         M68kAddressRegisterImpl(ADDRESS_REGISTER)
           PsiElement(M68kTokenType.REG_SP)('sp')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kDataRegisterImpl(DATA_REGISTER)
-          PsiElement(M68kTokenType.DREG)('d0')
-        M68kDataWidthImpl(DATA_WIDTH)
-          PsiElement(M68kTokenType.OPSIZE_W)('.w')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kDataRegisterImpl(DATA_REGISTER)
+            PsiElement(M68kTokenType.DREG)('d0')
+          M68kDataWidthImpl(DATA_WIDTH)
+            PsiElement(M68kTokenType.OPSIZE_W)('.w')
         PsiElement(M68kTokenType.ROUND_R)(')')
       PsiElement(M68kTokenType.SEPARATOR)(',')
       M68kAddressRegisterIndirectWithIndexNewAddressingModeImpl(ADDRESS_REGISTER_INDIRECT_WITH_INDEX_NEW_ADDRESSING_MODE)
@@ -23,7 +24,8 @@ Assembly File: a.asm
         M68kAddressRegisterImpl(ADDRESS_REGISTER)
           PsiElement(M68kTokenType.AREG)('a1')
         PsiElement(M68kTokenType.SEPARATOR)(',')
-        M68kAddressRegisterImpl(ADDRESS_REGISTER)
-          PsiElement(M68kTokenType.AREG)('a3')
+        M68kIndexRegisterImpl(INDEX_REGISTER)
+          M68kAddressRegisterImpl(ADDRESS_REGISTER)
+            PsiElement(M68kTokenType.AREG)('a3')
         PsiElement(M68kTokenType.ROUND_R)(')')
   PsiElement(M68kTokenType.EOL)('\n')
\ No newline at end of file