X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/77ab69d7bb0902e6ebf0994159ed2205f8413e34..b057a5d6e6db6db06ae33703ca72cd235eec91d6:/core/insn_alu_ext.v

diff --git a/core/insn_alu_ext.v b/core/insn_alu_ext.v
new file mode 100644
index 0000000..1b7825b
--- /dev/null
+++ b/core/insn_alu_ext.v
@@ -0,0 +1,45 @@
+`ifdef EXECUTE
+	`INSN_ALU_EXT: begin
+		if ((opcode[2:0] == `INSN_reg_dHL) && (cycle == 0))
+			`EXEC_READ(`_HL)
+		else begin
+			`EXEC_INC_PC
+			case (opcode[2:0])
+			`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_dHL:  tmp <= rdata;
+			endcase
+		end
+	end
+`endif
+
+`ifdef WRITEBACK
+	`INSN_ALU_EXT: begin
+		if (opcode[2:0] == `INSN_reg_dHL) begin
+			if(cycle == 0) begin end
+			else if(cycle == 1) begin
+				`EXEC_WRITE(`_HL, alu_res)
+			end else begin
+				`EXEC_NEWCYCLE
+			end
+		end else begin
+			case(opcode[2:0])
+			`INSN_reg_B: `_B <= alu_res;
+			`INSN_reg_C: `_C <= alu_res;
+			`INSN_reg_D: `_D <= alu_res;
+			`INSN_reg_E: `_E <= alu_res;
+			`INSN_reg_H: `_H <= alu_res;
+			`INSN_reg_L: `_L <= alu_res;
+			`INSN_reg_A: `_A <= alu_res;
+			`INSN_reg_dHL: begin end /* eat dicks */
+			endcase
+			`_F <= {f_res,`_F[3:0]};
+			`EXEC_NEWCYCLE
+		end
+	end
+`endif