diff --git a/r2plugin/TESTING.md b/r2plugin/TESTING.md
new file mode 100644
index 0000000..7de4fe4
--- /dev/null
+++ b/r2plugin/TESTING.md
@@ -0,0 +1,65 @@
+# Decoder Test Coverage
+
+Verified = disassembly checked against open21xx assembler output.
+Structural = implemented from reference docs, no assembler test.
+
+| Type | Description                    | Status     | Test file              |
+|------|--------------------------------|------------|------------------------|
+| 1    | Compute + DM + PM             | Verified   | fir.bin, iir.bin       |
+| 3    | Direct memory read/write      | Verified   | fir.bin (DM writes)    |
+| 4    | Compute + DM/PM postmodify    | Verified   | fir.bin, iir.bin       |
+| 6    | Dreg = Imm16                  | Verified   | isa_test.bin           |
+| 7    | Reg1/Reg2 = Imm16             | Verified   | isa_test.bin           |
+| 8    | Compute + Dreg move           | Verified   | type8_test.dsp         |
+| 9    | Conditional compute            | Verified   | type9_test.dsp         |
+| 9a   | Unconditional register compute | Verified   | type9_test.dsp         |
+| 10   | Conditional jump (13-bit rel) | Verified   | isa_test.bin           |
+| 10a  | Unconditional jump (16-bit)   | Verified   | isa_test.bin           |
+| 11   | DO UNTIL (12-bit rel)         | Verified   | isa_test.bin, fir.bin  |
+| 12   | Shift + DM/PM                 | Structural | —                      |
+| 14   | Shift + Dreg move             | Structural | —                      |
+| 15   | Shift immediate               | Verified   | isa_test.bin           |
+| 16   | Conditional shift             | Structural | —                      |
+| 17   | Reg = Reg                     | Verified   | isa_test.bin           |
+| 18   | Mode control (ENA/DIS)        | Verified   | type18_test.dsp        |
+| 19   | Indirect jump/call            | Structural | —                      |
+| 20   | RTS/RTI                       | Verified   | isa_test.bin, fir.bin  |
+| 21   | MODIFY (Ireg += Mreg)         | Structural | —                      |
+| 21a  | MODIFY (Ireg += Imm8)         | Structural | —                      |
+| 22   | DM = Data16 (2-word)          | Structural | —                      |
+| 22a  | PM = Data24 (2-word)          | Structural | —                      |
+| 23   | DIVQ                          | Structural | —                      |
+| 24   | DIVS                          | Structural | —                      |
+| 25   | SAT MR/SR                     | Verified   | isa_test.bin           |
+| 26   | Push/Pop/Flush Cache          | Structural | —                      |
+| 29   | DM read/write imm modify      | Structural | —                      |
+| 30   | NOP                           | Verified   | isa_test.bin           |
+| 31   | IDLE                          | Structural | —                      |
+| 32   | Any Reg <-> DM/PM (DAG)       | Structural | —                      |
+| 32a  | DAG reg store + transfer      | Structural | —                      |
+| 33   | Reg3 = Data12                 | Verified   | isa_test.bin           |
+| 34   | IO register read/write        | Structural | —                      |
+| 35   | System register read/write    | Structural | —                      |
+| 36   | Long jump/call (2-word)       | Structural | —                      |
+| 37   | SETINT/CLRINT                 | Structural | —                      |
+
+## Priority gaps for assembler verification
+
+High (used in real firmware, likely to encounter):
+- Type 12: Shift + memory (common in FIR output scaling)
+- Type 29: DM immediate modify (common for stack-like access)
+- Type 32: Any Reg <-> DM/PM (general register save/restore)
+- Type 19: Indirect jump (function pointer dispatch)
+
+Medium (less common but structurally complex):
+- Type 22/22a: 2-word immediate write (initialization code)
+- Type 36: Long jump/call (large firmware images)
+- Type 32a: DAG store + transfer (DSP loop setup)
+
+Low (rare or simple):
+- Type 16: Conditional shift
+- Type 21/21a: MODIFY
+- Type 23/24: DIVQ/DIVS
+- Type 26: Push/Pop
+- Type 34/35: IO/System registers
+- Type 37: SETINT/CLRINT
diff --git a/r2plugin/asm_adsp219x.c b/r2plugin/asm_adsp219x.c
index e076daf..b8056d5 100644
--- a/r2plugin/asm_adsp219x.c
+++ b/r2plugin/asm_adsp219x.c
@@ -1,7 +1,12 @@
-/* asm_adsp219x.c -- Full Radare2 arch plugin for Analog Devices ADSP-219x
+/* asm_adsp219x.c -- Radare2 arch plugin for Analog Devices ADSP-219x
    Copyright (C) 2026 Dr. Christian Giessen
 
-   This file implements the complete ADSP-219x Instruction Set (Types 1-37).  */
+   Decodes most of the ADSP-219x instruction set (Types 1-37).
+   Verified against open21xx assembler output for Types 1, 3, 4,
+   6, 7, 8, 9, 9a, 10, 10a, 11, 15, 17, 18, 20, 25, 33.
+   Structurally implemented but not yet assembler-verified:
+   Types 12, 14, 16, 19, 21, 21a, 22, 22a, 23, 24, 26, 29,
+   30, 31, 32, 32a, 34, 35, 36, 37.  */
 
 #include <r_arch.h>