update sys, add toggle for PPU reset behavior (#424)

Author: Kitrinx

NES.sv

@@ -271,6 +271,7 @@ parameter CONF_STR = {
 	"P3o9,Pause when OSD is open,Off,On;",
 	"P4,Advanced;",
 	"P4-;",
+	"P4O[64],PPU Reset Behavior,Famicom,NES;",
 	"P4OQ,Video Dijitter,Enabled,Disabled;",
 	"- ;",
 	"R0,Reset;",
@@ -303,7 +304,7 @@ wire [23:0] joyA_unmod;
 wire [10:0] ps2_key;
 wire [1:0] buttons;
 
-wire [63:0] status;
+wire [127:0] status;
 
 wire arm_reset = status[0];
 wire pal_video = |status[24:23];
@@ -844,6 +845,7 @@ end
 NES nes (
 	.clk             (clk),
 	.reset_nes       (reset_nes),
+	.ppu_rst_behavior(status[64]),
 	.cold_reset      (downloading & (type_fds | type_nes)),
 	.pausecore       (pausecore),
 	.corepaused      (corepaused),

rtl/apu.sv

@@ -356,7 +356,7 @@ module TriangleChan (
 			endcase
 		end
 
-		if (reset) begin
+		if (cold_reset) begin
 			sample_latch <= 4'hF;
 			Period <= 0;
 			TimerCtr <= 0;

rtl/nes.v

@@ -74,6 +74,7 @@ endmodule
 module NES(
 	input         clk,
 	input         reset_nes,
+	input         ppu_rst_behavior,
 	input         cold_reset,
 	input         pausecore,
 	output        corepaused,
@@ -575,6 +576,7 @@ assign scanline = (corepause_active) ? scanline_paused : scanline_ppu;
 
 PPU ppu(
 	.clk              (clk),
+	.rst_behavior     (ppu_rst_behavior),
 	.ce               (ppu_ce),
 	.reset            (reset),
 	.sys_type         (sys_type),

rtl/ppu.sv

@@ -1073,6 +1073,7 @@ endmodule  // PaletteRam
 
 module PPU(
 	input         clk,
+	input         rst_behavior,
 	input         ce,
 	input         reset,            // input clock  21.48 MHz / 4. 1 clock cycle = 1 pixel
 	input         cold_reset,       // power cycle
@@ -1149,7 +1150,7 @@ initial begin
 	enable_playfield = 0;
 	enable_objects = 0;
 	emphasis = 0;
-	clear = 1;
+	clear = 0;
 end
 
 reg nmi_occured;         // True if NMI has occured but not cleared.
@@ -1626,7 +1627,7 @@ always @(posedge clk) begin
 
 	if (reset) begin
 		latched_dout <= 8'd0;
-		clear <= 1;
+		clear <= rst_behavior;
 	end
 
 	if (SaveStateBus_load) begin