From: Joshua Wise <joshua@rebirth.joshuawise.com>
Date: Mon, 31 Mar 2008 00:23:36 +0000 (-0400)
Subject: RST insn
X-Git-Url: http://git.joshuawise.com/fpgaboy.git/commitdiff_plain/1e03e0219589e33a57c34046428f09b9228c99b4?ds=inline;hp=d3938806a2b49df44ac55ea4b2a43c6a3f15011d

RST insn
---

diff --git a/FPGABoy.ise b/FPGABoy.ise
index 2e6073a..8260443 100644
Binary files a/FPGABoy.ise and b/FPGABoy.ise differ
diff --git a/GBZ80Core.v b/GBZ80Core.v
index 3e15ebf..75f9722 100644
--- a/GBZ80Core.v
+++ b/GBZ80Core.v
@@ -34,6 +34,7 @@
 `define INSN_LDx_AHL			8'b001xx010	// LDD/LDI A,(HL) / (HL),A
 `define INSN_ALU8				8'b10xxxxxx	// 10 xxx yyy
 `define INSN_NOP				8'b00000000
+`define INSN_RST				8'b11xxx111
 
 `define INSN_reg_A		3'b111
 `define INSN_reg_B		3'b000
@@ -338,6 +339,26 @@ module GBZ80Core(
 				`EXEC_NEWCYCLE;
 				`EXEC_INC_PC;
 			end
+			`INSN_RST: begin
+				case (cycle)
+				0: begin
+						wr <= 1;
+						address <= {registers[`REG_SPH],registers[`REG_SPL]}-1;
+						wdata <= registers[`REG_PCH];
+					end
+				1: begin
+						wr <= 1;
+						address <= {registers[`REG_SPH],registers[`REG_SPL]}-2;
+						wdata <= registers[`REG_PCL];
+					end
+				2:	begin /* wee */ end
+				3: begin
+						`EXEC_NEWCYCLE;
+						{registers[`REG_PCH],registers[`REG_PCL]} <=
+							{10'b0,opcode[5:3],3'b0};
+					end
+				endcase
+			end
 			default:
 				$stop;
 			endcase
@@ -563,6 +584,18 @@ module GBZ80Core(
 				end
 			end
 			`INSN_NOP: begin /* NOP! */ end
+			`INSN_RST: begin
+				case (cycle)
+				0:	cycle <= 1;
+				1:	cycle <= 2;
+				2: cycle <= 3;
+				3:	begin
+						cycle <= 0;
+						{registers[`REG_SPH],registers[`REG_SPL]} <=
+							{registers[`REG_SPH],registers[`REG_SPL]}-2;
+					end
+				endcase
+			end
 			endcase
 			state <= `STATE_FETCH;
 		end
diff --git a/rom.hex b/rom.hex
index a465631..b54409e 100644
--- a/rom.hex
+++ b/rom.hex
@@ -20,8 +20,8 @@ C1
 A8
 // LD (HL), A
 77
-// HALT
-76
+// RST 00h
+C7
 
 @100
 02