diff --git a/MC6809/inc/mc6809.h b/MC6809/inc/mc6809.h
index 969920a..64b649a 100644
--- a/MC6809/inc/mc6809.h
+++ b/MC6809/inc/mc6809.h
@@ -184,6 +184,7 @@ namespace EightBit {
 		void cmp(uint8_t operand, uint8_t data);
 		void cmp(register16_t operand, register16_t data);
 		uint8_t com(uint8_t operand);
+		void cwai(uint8_t data);
 		uint8_t neg(uint8_t operand);
 
 		register16_t m_d;
diff --git a/MC6809/src/mc6809.cpp b/MC6809/src/mc6809.cpp
index 5a61141..003f15e 100644
--- a/MC6809/src/mc6809.cpp
+++ b/MC6809/src/mc6809.cpp
@@ -155,6 +155,9 @@ int EightBit::mc6809::executeUnprefixed(uint8_t opcode) {
 	case 0x63:	addCycles(6);	BUS().write(com(AM_indexed_byte()));	break;		// COM (COM indexed)
 	case 0x73:	addCycles(7);	BUS().write(com(AM_extended_byte()));	break;		// COM (COM extended)
 
+	// CWAI
+	case 0x3c:	addCycles(20);	cwai(AM_direct_byte());					break;		// CWAI (CWAI direct)
+
 	default:
 		UNREACHABLE;
 	}
@@ -449,3 +452,16 @@ uint8_t EightBit::mc6809::com(uint8_t operand) {
 	setFlag(CC(), CF);
 	return result;
 }
+
+void EightBit::mc6809::cwai(uint8_t data) {
+	CC() &= data;
+	pushWord(PC());
+	pushWord(U());
+	pushWord(Y());
+	pushWord(X());
+	push(DP());
+	push(B());
+	push(A());
+	push(CC());
+	halt();
+}
\ No newline at end of file