X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/5f7913a508f18ca9664223dde5ae16608595a08b..81358c71b258a72a2777bba0a0b4a82a7cae298a:/insn_push_reg.v

diff --git a/insn_push_reg.v b/insn_push_reg.v
new file mode 100644
index 0000000..7a32301
--- /dev/null
+++ b/insn_push_reg.v
@@ -0,0 +1,43 @@
+`ifdef EXECUTE
+	`INSN_PUSH_reg: begin	/* PUSH is 16 cycles! */
+		case (cycle)
+		0:	begin
+				wr <= 1;
+				address <= {registers[`REG_SPH],registers[`REG_SPL]}-1;
+				case (opcode[5:4])
+				`INSN_stack_AF:	wdata <= registers[`REG_A];
+				`INSN_stack_BC:	wdata <= registers[`REG_B];
+				`INSN_stack_DE:	wdata <= registers[`REG_D];
+				`INSN_stack_HL:	wdata <= registers[`REG_H];
+				endcase
+			end
+		1:	begin
+				wr <= 1;
+				address <= {registers[`REG_SPH],registers[`REG_SPL]}-2;
+				case (opcode[5:4])
+				`INSN_stack_AF:	wdata <= registers[`REG_F];
+				`INSN_stack_BC:	wdata <= registers[`REG_C];
+				`INSN_stack_DE:	wdata <= registers[`REG_E];
+				`INSN_stack_HL:	wdata <= registers[`REG_L];
+				endcase
+			end
+		2:	begin /* Twiddle thumbs. */ end
+		3:	begin
+				`EXEC_NEWCYCLE;
+				`EXEC_INC_PC;
+			end
+		endcase
+	end
+`endif
+
+`ifdef WRITEBACK
+	`INSN_PUSH_reg: begin	/* PUSH is 16 cycles! */
+		case (cycle)
+		0:	begin /* type F */ end
+		1:	begin /* type F */ end
+		2:	begin /* type F */ end
+		3:	{registers[`REG_SPH],registers[`REG_SPL]} <=
+				{registers[`REG_SPH],registers[`REG_SPL]} - 2;
+		endcase
+	end
+`endif