gateware

commit ede20da576e18b5d89e9144eecec397d23a972e6
parent 34c05bff2d4c3bc0e1c60eece88b0ef116a05a9d
Author: Brian Swetland <swetland@frotz.net>
Date:   Sat, 24 Nov 2018 23:44:25 -0800

a16/d16: use the "true" nop rather than the alu nop

The alu nop is Rx = Rx + 0 which actually writes to the
register file and until we sort out hazards it is a bit
annoying.

Diffstat:
M
src/a16v4.c
 | 
8
+++++---
M
src/d16v4.c
 | 
4
++--

2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/src/a16v4.c b/src/a16v4.c
@@ -440,6 +440,7 @@ void expect_register(unsigned got) {
 
 
 #define OP_ALU_RC_RA_RB         0x0000
+#define OP_EXPANSION            0x0001
 #define OP_EXT                  0x0002
 #define OP_MOV_RC_S9            0x0003
 #define OP_LW_RC_RA_S6          0x0004
@@ -451,7 +452,8 @@ void expect_register(unsigned got) {
 #define OP_B_RA                 0x0027
 #define OP_BL_RA                0x0037
 #define OP_ALU_RC_RA_S6         0x0008
-#define OP_NOP                  0x0008
+#define OP_NOP_EXP              0x0001
+#define OP_NOP_ALU              0x0008
 
 #define ALU_ADD 0
 #define ALU_SUB 1
@@ -491,7 +493,7 @@ void assemble_line(int n, unsigned *tok, unsigned *num, char **str) {
 		/* blank lines are fine */
 		return;
 	case tNOP:
-		emit(OP_NOP);
+		emit(OP_NOP_EXP);
 		return;
 	case tNOT:
 		/* XOR rX, rX, -1 */
@@ -573,7 +575,7 @@ void assemble_line(int n, unsigned *tok, unsigned *num, char **str) {
 		expect_register(T1);
 		expect(tCOMMA, T2);
 		expect(tNUMBER, T3);
-		emit(OP_NOP); //TODO
+		emit(OP_NOP_EXP); //TODO
 		return;
 	case tHALT:
 		emit(0xFFFF);
diff --git a/src/d16v4.c b/src/d16v4.c
@@ -151,7 +151,7 @@ struct {
 	const char *fmt;
 } decode[] = {
 	{ 0b0000000000001111, 0b0000000000000000, "@F @C, @A, @B" },
-	{ 0b0000000000001111, 0b0000000000000001, "UND" },
+	{ 0b0000000000001111, 0b0000000000000001, "NOP (EXT)" },
 	{ 0b0000000000001111, 0b0000000000000010, "EXT @e" },
 	{ 0b0000000000001111, 0b0000000000000011, "MOV @C, +@9" },
 	{ 0b0000000000001111, 0b0000000000000100, "LW @C, [@A, @6]" },
@@ -162,7 +162,7 @@ struct {
 	{ 0b0000000000111111, 0b0000000000010111, "BNZ @A, @7" },
 	{ 0b1111110001111111, 0b0000000000100111, "B @A" },
 	{ 0b1111110001111111, 0b0000000000110111, "BL @A" },
-	{ 0b1111111111111111, 0b0000000000001000, "NOP" }, // ADD R0, R0, 0
+	{ 0b1111111111111111, 0b0000000000001000, "NOP (ALU)" }, // ADD R0, R0, 0
 	{ 0b1111110000001111, 0b0000000000001000, "MOV @C, @A" }, // ADD Rc, Ra, 0
 	{ 0b1111110000001111, 0b1111110000001100, "NOT @C, @A" }, // XOR Rc, Ra, -1
 	{ 0b0000000000001000, 0b0000000000001000, "@f @C, @A, +@6" },