From ff3e8e0a71122ebd6ab694b6432d8a67d4455f06 Mon Sep 17 00:00:00 2001
From: paulb-nl <boumanpaul@gmail.com>
Date: Wed, 28 Jun 2023 13:20:54 +0200
Subject: [PATCH] CD: Add VBlank IRQ mask

---
 neogeo.sv            | 3 +++
 rtl/cd/cd.sv         | 4 ++++
 rtl/video/irq.v      | 5 +++--
 rtl/video/lspc2_a2.v | 6 ++++--
 4 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/neogeo.sv b/neogeo.sv
index b823ad9..5955005 100644
--- a/neogeo.sv
+++ b/neogeo.sv
@@ -791,6 +791,7 @@ wire CD_USE_SPR, CD_USE_FIX, CD_USE_Z80;
 wire CD_UPLOAD_EN;
 wire CD_BANK_PCM;
 wire CD_IRQ;
+wire CD_VBLANK_IRQ_EN;
 wire DMA_RUNNING, DMA_WR_OUT, DMA_RD_OUT;
 wire [15:0] DMA_DATA_OUT;
 wire [23:0] DMA_ADDR_IN;
@@ -901,6 +902,7 @@ cd_sys cdsystem(
 	.CD_TR_WR_DATA(CD_TR_WR_DATA), .CD_TR_WR_ADDR(CD_TR_WR_ADDR),
 	.CD_UPLOAD_EN(CD_UPLOAD_EN),
 	.CD_IRQ(CD_IRQ), .IACK(IACK),
+	.CD_VBLANK_IRQ_EN(CD_VBLANK_IRQ_EN),
 	.CDD_STATUS_IN(CDD_STATUS), .CDD_STATUS_LATCH(CDD_STATUS_LATCH),
 	.CDD_COMMAND_DATA(CDD_COMMAND_DATA), .CDD_COMMAND_SEND(CDD_COMMAND_SEND),
 	.CD_DATA_DOWNLOAD(CD_DATA_DOWNLOAD), .CD_DATA_WR(CD_DATA_WR),
@@ -1960,6 +1962,7 @@ lspc2_a2	LSPC(
 	.FVRAM_DATA_IN(FAST_VRAM_DATA_IN), .FVRAM_DATA_OUT(FAST_VRAM_DATA_OUT),
 	.CWE(CWE),
 	.VMODE(video_mode),
+	.CD_VBLANK_IRQ_EN(CD_VBLANK_IRQ_EN | ~SYSTEM_CDx),
 	.FIXMAP_ADDR(FIXMAP_ADDR)	// Extracted for NEO-CMC
 );
 
diff --git a/rtl/cd/cd.sv b/rtl/cd/cd.sv
index 04efdf5..62dcf3a 100644
--- a/rtl/cd/cd.sv
+++ b/rtl/cd/cd.sv
@@ -55,6 +55,8 @@ module cd_sys(
 	output reg [19:1] CD_TR_WR_ADDR,
 	output reg CD_UPLOAD_EN, // The bios writes to Z80 RAM without CD_UPLOAD_EN enabled. Maybe this is only watchdog disable?
 
+	output CD_VBLANK_IRQ_EN,
+
 	input IACK,
 	output reg CD_IRQ,
 	
@@ -790,6 +792,8 @@ module cd_sys(
 		end
 	endfunction
 
+	assign CD_VBLANK_IRQ_EN = &{REG_FF0004[5:4]};
+
 	assign M68K_DATA = (SYSTEM_CDx & ~nAS & M68K_RW & IACK) ? {8'h00, CD_IRQ_VECTOR} :		// Vectored interrupt handler
 							(READING & {M68K_ADDR[11:1], 1'b0} == 12'h004) ? {4'h0, REG_FF0004} :
 							(READING & {M68K_ADDR[11:1], 1'b0} == 12'h11C) ? {3'b110, CD_LID, CD_JUMPERS, 8'h00} :	// Top mech
diff --git a/rtl/video/irq.v b/rtl/video/irq.v
index 1b3b956..b74608a 100644
--- a/rtl/video/irq.v
+++ b/rtl/video/irq.v
@@ -19,7 +19,8 @@ module irq(
 	input [2:0] ACK_BITS,
 	input RESET_IRQ,
 	input TIMER_IRQ,
-	input VBL_IRQ,
+	input VBL_IRQ,
+	input CD_VBL_EN,
 	input CLK,
 	output IPL0, IPL1
 );
@@ -36,7 +37,7 @@ module irq(
 	wire B56_Q, B56_nQ, B52_Q, B52_nQ, C52_Q;
 	FD3 B56(RESET_IRQ, 1'b0, ACK[0], B56_Q, B56_nQ);
 	FD3 B52(TIMER_IRQ, 1'b0, ACK[1], B52_Q, B52_nQ);
-	FD3 C52(VBL_IRQ, 1'b0, ACK[2], C52_Q);
+	FD3 C52(VBL_IRQ, ~CD_VBL_EN, ACK[2], C52_Q);
 	
 	// B49
 	wire B49_OUT = B52_Q | B56_nQ;
diff --git a/rtl/video/lspc2_a2.v b/rtl/video/lspc2_a2.v
index d4b7ee1..0eff353 100644
--- a/rtl/video/lspc2_a2.v
+++ b/rtl/video/lspc2_a2.v
@@ -65,7 +65,9 @@ module lspc2_a2(
 	output nPBUS_OUT_EN,
 	
 	input VMODE,
-	
+
+	input CD_VBLANK_IRQ_EN,
+
 	output [14:0] FIXMAP_ADDR		// Extracted for NEO-CMC
 );
 
@@ -589,7 +591,7 @@ module lspc2_a2(
 	resetp RSTP(CLK_24MB, RESET, nRESETP);
 	
 	wire BNK;
-	irq IRQ(WR_IRQ_ACK, M68K_DATA[2:0], RESET, D46A_OUT, BNK, LSPC_6M, IPL0, IPL1);
+	irq IRQ(WR_IRQ_ACK, M68K_DATA[2:0], RESET, D46A_OUT, BNK, CD_VBLANK_IRQ_EN, LSPC_6M, IPL0, IPL1);
 	
 	wire Q53_CO, FLIP, P50_CO;
 	videosync VS(CLK_24MB, LSPC_3M, LSPC_1_5M, Q53_CO, nRESETP, VMODE, PIXELC, RASTERC, HSYNC, VSYNC, BNK,