Fix interrupts / Crystal City

Author: callsop

CpuCommon.h

@@ -0,0 +1,71 @@
+#pragma once
+
+//  Copyright 2015 by Joseph Forgion
+//  This file is part of VCC (Virtual Color Computer).
+//
+//  VCC (Virtual Color Computer) is free software: you can redistribute it and/or
+//  modify it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  VCC (Virtual Color Computer) is distributed in the hope that it will be
+//  useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License along
+//  with VCC. If not, see <http://www.gnu.org/licenses/>.
+//
+//  2025/05/22 - Craig Allsop - Interrupt handling.
+//
+
+// no includes here, included by 6809.c, 6309.c
+
+//
+// Access cc flags as boolean
+//
+static inline bool CC(char flag) 
+{
+	return cc[flag] ? true : false; 
+}
+
+//
+// Interrupt lines reading from output of the latch
+//
+static inline bool FIRQ() { return InterruptLatch.Q & Bit(INT_FIRQ) ? true : false; }
+static inline bool IRQ() { return InterruptLatch.Q & Bit(INT_IRQ) ? true : false; }
+static inline bool NMI() { return InterruptLatch.Q & Bit(INT_NMI) ? true : false; }
+
+//
+// Latch the interrupt lines
+// This done per instruction top of state A (see figure 15, 6809 spec) and also waiting in SYNC
+//
+static inline void LatchInterrupts()
+{
+	uint8_t OR = 0;
+	for (int is = 0; is < IS_MAX; ++is)
+		OR |= InterruptLine[is];
+
+	// clock next input
+	InterruptLatch.Clock(OR);
+}
+
+//
+// Clear the nmi interrupt
+//
+static inline void ClearNMI()
+{
+	InterruptLine[IS_NMI] &= BitMask(INT_NMI);
+	LatchInterrupts();
+}
+
+//
+// Clear state of all interrupt lines
+//
+static inline void ClearInterrupts()
+{
+	for (int is = 0; is < IS_MAX; ++is)
+		InterruptLine[is] = 0;
+	InterruptLatch.Reset();
+}
+

FD502/defines.h

@@ -36,11 +36,5 @@ This file is part of VCC (Virtual Color Computer).
 #define QUERY 255
 #define INDEXTIME ((LINESPERFIELD * TARGETFRAMERATE)/5)
 
-
-//Common CPU defs
-#define IRQ		1
-#define FIRQ	2
-#define NMI		3
-
 #endif
 

FD502/fd502.cpp

@@ -30,15 +30,16 @@ This file is part of VCC (Virtual Color Computer).
 #include "wd1793.h"
 #include "distortc.h"
 #include "fd502.h"
-#include "..\fileops.h"
+#include "../fileops.h"
+#include "../MachineDefs.h"
 #define EXTROMSIZE 16384
 
 using namespace std;
 
 extern DiskInfo Drive[5];
 typedef unsigned char (*MEMREAD8)(unsigned short);
 typedef void (*MEMWRITE8)(unsigned char,unsigned short);
-typedef void (*ASSERTINTERUPT) (unsigned char,unsigned char);
+typedef void (*ASSERTINTERUPT)(InterruptSource, Interrupt);
 typedef void (*DMAMEMPOINTERS) ( MEMREAD8,MEMWRITE8);
 typedef void (*DYNAMICMENUCALLBACK)( char *,int, int);
 static unsigned char ExternalRom[EXTROMSIZE];
@@ -47,7 +48,7 @@ static unsigned char RGBDiskRom[EXTROMSIZE];
 static char FloppyPath[MAX_PATH];
 static char RomFileName[MAX_PATH]="";
 static char TempRomFileName[MAX_PATH]="";
-static void (*AssertInt)(unsigned char,unsigned char)=NULL;
+void (*AssertInt)(InterruptSource,Interrupt)=NULL;
 static void (*DynamicMenuCallback)( char *,int, int)=NULL;
 static unsigned char (*MemRead8)(unsigned short);
 static void (*MemWrite8)(unsigned char,unsigned short);
@@ -244,11 +245,7 @@ extern "C"
 	}
 }
 
-void CPUAssertInterupt(unsigned char Interupt,unsigned char Latencey)
-{
-	AssertInt(Interupt,Latencey);
-	return;
-}
+
 
 void CenterDialog(HWND hDlg)
 {

FD502/fd502.h

@@ -17,7 +17,10 @@ This file is part of VCC (Virtual Color Computer).
     You should have received a copy of the GNU General Public License
     along with VCC (Virtual Color Computer).  If not, see <http://www.gnu.org/licenses/>.
 */
-void CPUAssertInterupt(unsigned char,unsigned char);
+
+#include "../MachineDefs.h"
+
+extern "C" void (*AssertInt)(InterruptSource, Interrupt);
 void BuildDynaMenu(void);
 #define	HEAD 0
 #define SLAVE 1

FD502/wd1793.c

@@ -36,6 +36,7 @@ This file is part of VCC (Virtual Color Computer).
 #include <stdlib.h>
 #include <winioctl.h>
 #include "defines.h"
+#include "../MachineDefs.h"
 #include "wd1793.h"
 #include "fd502.h"
 #include "fdrawcmd.h"	// http://simonowen.com/fdrawcmd/
@@ -990,7 +991,7 @@ void DispatchCommand(unsigned char Tmp)
 			StatusReg=READY;
 			ExecTimeWaiter=1;
 			if ((Tmp & 15) != 0)
-				CPUAssertInterupt(NMI,0);
+				AssertInt(IS_NMI, INT_NMI);
 //			WriteLog("FORCEINTERUPT",0);
 			break;
 
@@ -1393,9 +1394,9 @@ long GetSectorInfo (SectorInfo *Sector,unsigned char *TempBuffer)
 void CommandDone(void)
 {
 	if (InteruptEnable)
-		CPUAssertInterupt(NMI,0);
-		TransferBufferSize=0;
-		CurrentCommand=IDLE;
+		AssertInt(IS_NMI, INT_NMI);
+	TransferBufferSize=0;
+	CurrentCommand=IDLE;
 }
 
 //Stolen from MESS

HardDisk/defines.h

@@ -36,11 +36,5 @@ This file is part of VCC (Virtual Color Computer).
 #define QUERY 255
 #define INDEXTIME ((LINESPERFIELD * TARGETFRAMERATE)/5)
 
-
-//Common CPU defs
-#define IRQ		1
-#define FIRQ	2
-#define NMI		3
-
 #endif
 

HardDisk/harddisk.cpp

@@ -25,7 +25,8 @@ This file is part of VCC (Virtual Color Computer).
 #include "cc3vhd.h"
 #include "defines.h"
 #include "cloud9.h"
-#include "..\fileops.h"
+#include "../fileops.h"
+#include "../MachineDefs.h"
 
 #define DEF_HD_SIZE 132480
 
@@ -38,10 +39,10 @@ static char HardDiskPath[MAX_PATH];
 
 typedef unsigned char (*MEMREAD8)(unsigned short);
 typedef void (*MEMWRITE8)(unsigned char,unsigned short);
-typedef void (*ASSERTINTERUPT) (unsigned char,unsigned char);
+typedef void (*ASSERTINTERUPT)(InterruptSource, Interrupt);
 typedef void (*DMAMEMPOINTERS) ( MEMREAD8,MEMWRITE8);
 typedef void (*DYNAMICMENUCALLBACK)( char *,int, int);
-static void (*AssertInt)(unsigned char,unsigned char)=NULL;
+static void (*AssertInt)(InterruptSource, Interrupt)=NULL;
 static unsigned char (*MemRead8)(unsigned short);
 static void (*MemWrite8)(unsigned char,unsigned short);
 static unsigned char *Memory=NULL;

MachineDefs.h

@@ -72,17 +72,23 @@ namespace VCC
 
 }
 
-// Common CPU defs
-#define IRQ		1
-#define FIRQ	2
-#define NMI		3
+// Common CPU defs (counting from 1 because legacy)
+enum Interrupt { INT_IRQ = 1, INT_FIRQ, INT_NMI };
 
+// Interrupt sources keep track of their own state, NMI is its own source and always uses this.
+enum InterruptSource { IS_NMI, IS_PIA0_HSYNC, IS_PIA0_VSYNC, IS_PIA1_CD, IS_PIA1_CART, IS_GIME, IS_MAX };
+
+// make nth bit 0-7
+inline constexpr uint8_t Bit(uint8_t n) { return 1 << n; }
+
+// make mask of nth bit 0-7
+inline constexpr uint8_t BitMask(uint8_t n) { return ~Bit(n); }
 
 extern void (*CPUInit)(void);
 extern int  (*CPUExec)(int);
 extern void (*CPUReset)(void);
-extern void (*CPUAssertInterupt)(unsigned char, unsigned char);
-extern void (*CPUDeAssertInterupt)(unsigned char);
+extern void (*CPUAssertInterupt)(InterruptSource, Interrupt);
+extern void (*CPUDeAssertInterupt)(InterruptSource, Interrupt);
 extern void (*CPUForcePC)(unsigned short);
 extern void (*CPUSetBreakpoints)(const std::vector<unsigned short>&);
 extern void (*CPUSetTraceTriggers)(const std::vector<unsigned short>&);

OpDecoder.cpp

@@ -123,11 +123,11 @@ namespace VCC { namespace Debugger
 	{
 		switch (irq)
 		{
-		case IRQ:
+		case INT_IRQ:
 			return IRQType::InterruptRequest;
-		case FIRQ:
+		case INT_FIRQ:
 			return IRQType::FastInterruptRequest;
-		case NMI:
+		case INT_NMI:
 			return IRQType::NonMaskableInterrupt;
 		}
 		return IRQType();

Ramdisk/defines.h

@@ -19,9 +19,4 @@
 #define INDEXTIME ((LINESPERFIELD * TARGETFRAMERATE)/5)
 
 
-//Common CPU defs
-#define IRQ		1
-#define FIRQ	2
-#define NMI		3
-