X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/b057a5d6e6db6db06ae33703ca72cd235eec91d6..99b9687942367fd256a797bcd1f67fec07f92a37:/core/insn_incdec_reg8.v

diff --git a/core/insn_incdec_reg8.v b/core/insn_incdec_reg8.v
index 58582b6..b7ed993 100644
--- a/core/insn_incdec_reg8.v
+++ b/core/insn_incdec_reg8.v
@@ -1,15 +1,17 @@
+`define INSN_INCDEC_reg8	9'b000xxx10x
+
 `ifdef EXECUTE
 	`INSN_INCDEC_reg8: begin
 		`EXEC_INC_PC
 		`EXEC_NEWCYCLE
 		case (opcode[5:3])
-		`INSN_reg_A:	tmp <= `_A;
-		`INSN_reg_B:	tmp <= `_B;
-		`INSN_reg_C:	tmp <= `_C;
-		`INSN_reg_D:	tmp <= `_D;
-		`INSN_reg_E:	tmp <= `_E;
-		`INSN_reg_H:	tmp <= `_H;
-		`INSN_reg_L:	tmp <= `_L;
+		`INSN_reg_A:	tmp <= `_A + (opcode[0] ? 8'hFF : 8'h01);
+		`INSN_reg_B:	tmp <= `_B + (opcode[0] ? 8'hFF : 8'h01);
+		`INSN_reg_C:	tmp <= `_C + (opcode[0] ? 8'hFF : 8'h01);
+		`INSN_reg_D:	tmp <= `_D + (opcode[0] ? 8'hFF : 8'h01);
+		`INSN_reg_E:	tmp <= `_E + (opcode[0] ? 8'hFF : 8'h01);
+		`INSN_reg_H:	tmp <= `_H + (opcode[0] ? 8'hFF : 8'h01);
+		`INSN_reg_L:	tmp <= `_L + (opcode[0] ? 8'hFF : 8'h01);
 		endcase
 	end
 `endif
@@ -17,18 +19,19 @@
 `ifdef WRITEBACK
 	`INSN_INCDEC_reg8: begin
 		case (opcode[5:3])
-		`INSN_reg_A:	`_A <= tmp + (opcode[0] ? 8'hFF : 8'h01);
-		`INSN_reg_B:	`_B <= tmp + (opcode[0] ? 8'hFF : 8'h01);
-		`INSN_reg_C:	`_C <= tmp + (opcode[0] ? 8'hFF : 8'h01);
-		`INSN_reg_D:	`_D <= tmp + (opcode[0] ? 8'hFF : 8'h01);
-		`INSN_reg_E:	`_E <= tmp + (opcode[0] ? 8'hFF : 8'h01);
-		`INSN_reg_H:	`_H <= tmp + (opcode[0] ? 8'hFF : 8'h01);
-		`INSN_reg_L:	`_L <= tmp + (opcode[0] ? 8'hFF : 8'h01);
+		`INSN_reg_A:	`_A <= tmp;
+		`INSN_reg_B:	`_B <= tmp;
+		`INSN_reg_C:	`_C <= tmp;
+		`INSN_reg_D:	`_D <= tmp;
+		`INSN_reg_E:	`_E <= tmp;
+		`INSN_reg_H:	`_H <= tmp;
+		`INSN_reg_L:	`_L <= tmp;
 		endcase
 		`_F <= {
-				((tmp + (opcode[0] ? 8'hFF : 8'h01)) == 8'h00) ? 1'b1 : 1'b0,
-				1'b0,
-				(({1'b0,tmp[3:0]} + (opcode[0] ? 5'h1F : 5'h01)) >> 4) ? 1'b1 : 1'b0,
-				`_F[4:0]};
+				(tmp == 8'h00) ? 1'b1 : 1'b0,	/* Z */
+				opcode[0],	 /* N */
+				(tmp[3:0] == (opcode[0] ? 4'hF : 4'h0)) ? 1'b1 : 1'b0,
+				`_F[4:0]
+			};
 	end
 `endif