Add timer status lock logic

src/emulator.c

@@ -333,6 +333,7 @@ uint32_t emulatorGetStateSize(){
    size += sizeof(uint64_t) * 4;//32.32 fixed point double, timerXCycleCounter and CPU cycle timers
    size += sizeof(int32_t);//pllWakeWait
    size += sizeof(uint32_t);//clk32Counter
+   size += sizeof(uint16_t) * 2;//timerStatusReadAcknowledge
    size += sizeof(uint8_t) * 2;//ads7846
    size += sizeof(uint16_t);//ads7846
    size += sizeof(uint8_t) * 7;//palmMisc
@@ -432,10 +433,14 @@ void emulatorSaveState(uint8_t* data){
    offset += sizeof(int32_t);
    writeStateValueUint32(data + offset, clk32Counter);
    offset += sizeof(uint32_t);
-   writeStateValueDouble(data + offset, timer1CycleCounter);
+   writeStateValueDouble(data + offset, timerCycleCounter[0]);
    offset += sizeof(uint64_t);
-   writeStateValueDouble(data + offset, timer2CycleCounter);
+   writeStateValueDouble(data + offset, timerCycleCounter[1]);
    offset += sizeof(uint64_t);
+   writeStateValueUint16(data + offset, timerStatusReadAcknowledge[0]);
+   offset += sizeof(uint16_t);
+   writeStateValueUint16(data + offset, timerStatusReadAcknowledge[1]);
+   offset += sizeof(uint16_t);
 
    //ADS7846
    writeStateValueUint8(data + offset, ads7846InputBitsLeft);
@@ -553,10 +558,14 @@ void emulatorLoadState(uint8_t* data){
    offset += sizeof(int32_t);
    clk32Counter = readStateValueUint32(data + offset);
    offset += sizeof(uint32_t);
-   timer1CycleCounter = readStateValueDouble(data + offset);
+   timerCycleCounter[0] = readStateValueDouble(data + offset);
    offset += sizeof(uint64_t);
-   timer2CycleCounter = readStateValueDouble(data + offset);
+   timerCycleCounter[1] = readStateValueDouble(data + offset);
    offset += sizeof(uint64_t);
+   timerStatusReadAcknowledge[0] = readStateValueUint16(data + offset);
+   offset += sizeof(uint16_t);
+   timerStatusReadAcknowledge[1] = readStateValueUint16(data + offset);
+   offset += sizeof(uint16_t);
 
    //ADS7846
    ads7846InputBitsLeft = readStateValueUint8(data + offset);

src/hardwareRegisters.c

@@ -15,8 +15,8 @@
 chip_t   chips[CHIP_END];
 int32_t  pllWakeWait;
 uint32_t clk32Counter;
-double   timer1CycleCounter;
-double   timer2CycleCounter;
+double   timerCycleCounter[2];
+uint16_t timerStatusReadAcknowledge[2];
 
 
 bool pllIsOn();
@@ -435,6 +435,14 @@ unsigned int getHwRegister16(unsigned int address){
    printUnknownHwAccess(address, 0, 16, false);
 #endif
    switch(address){
+
+      case TSTAT1:
+         timerStatusReadAcknowledge[0] = registerArrayRead16(TSTAT1);//active bits acknowledged
+         return registerArrayRead16(TSTAT1);
+
+      case TSTAT2:
+         timerStatusReadAcknowledge[1] = registerArrayRead16(TSTAT2);//active bits acknowledged
+         return registerArrayRead16(TSTAT2);
          
       //32 bit registers accessed as 16 bit
       case IMR:
@@ -466,8 +474,6 @@ unsigned int getHwRegister16(unsigned int address){
       case TCMP2:
       case TPRER1:
       case TPRER2:
-      case TSTAT1:
-      case TSTAT2:
       case SPICONT2:
       case SPIDATA2:
          //simple read, no actions needed
@@ -819,12 +825,20 @@ void setHwRegister16(unsigned int address, unsigned int value){
          setSpiCont2(value);
          break;
 
+      case TSTAT1:
+         //preserve any unread bits
+         registerArrayWrite16(TSTAT1, (value & timerStatusReadAcknowledge[0]) | (registerArrayRead16(TSTAT1) & ~timerStatusReadAcknowledge[0]));
+         break;
+
+      case TSTAT2:
+         //preserve any unread bits
+         registerArrayWrite16(TSTAT2, (value & timerStatusReadAcknowledge[1]) | (registerArrayRead16(TSTAT2) & ~timerStatusReadAcknowledge[1]));
+         break;
+
       case TCMP1:
       case TCMP2:
       case TPRER1:
       case TPRER2:
-      case TSTAT1:
-      case TSTAT2:
       case SPIDATA2:
          //simple write, no actions needed
          registerArrayWrite16(address, value);
@@ -891,8 +905,10 @@ void resetHwRegisters(){
    memset(palmReg, 0x00, REG_SIZE - BOOTLOADER_SIZE);
    clk32Counter = 0;
    pllWakeWait = -1;
-   timer1CycleCounter = 0.0;
-   timer2CycleCounter = 0.0;
+   timerCycleCounter[0] = 0.0;
+   timerCycleCounter[1] = 0.0;
+   timerStatusReadAcknowledge[0] = 0x0000;
+   timerStatusReadAcknowledge[1] = 0x0000;
    for(uint8_t chip = CHIP_BEGIN; chip < CHIP_END; chip++){
       chips[chip].enable = false;
       chips[chip].start = 0x00000000;

src/hardwareRegisters.h

@@ -58,8 +58,8 @@ typedef struct{
 extern chip_t   chips[];
 extern int32_t  pllWakeWait;
 extern uint32_t clk32Counter;
-extern double   timer1CycleCounter;
-extern double   timer2CycleCounter;
+extern double   timerCycleCounter[];
+extern uint16_t timerStatusReadAcknowledge[];
 
 //memory accessors
 unsigned int getHwRegister8(unsigned int address);

src/hardwareRegistersTiming.c.h

@@ -114,22 +114,22 @@ static inline void timer12Clk32(){
 
          case 0x0001://SYSCLK / timer prescaler
             if(pllIsOn())
-               timer1CycleCounter += sysclksPerClk32() / timer1Prescaler;
+               timerCycleCounter[0] += sysclksPerClk32() / timer1Prescaler;
             break;
 
          case 0x0002://SYSCLK / 16 / timer prescaler
             if(pllIsOn())
-               timer1CycleCounter += sysclksPerClk32() / 16.0 / timer1Prescaler;
+               timerCycleCounter[0] += sysclksPerClk32() / 16.0 / timer1Prescaler;
             break;
 
          default://CLK32 / timer prescaler
-            timer1CycleCounter += 1.0 / timer1Prescaler;
+            timerCycleCounter[0] += 1.0 / timer1Prescaler;
             break;
       }
 
-      if(timer1CycleCounter >= 1.0){
-         timer1Count += (uint16_t)timer1CycleCounter;
-         timer1CycleCounter -= (uint16_t)timer1CycleCounter;
+      if(timerCycleCounter[0] >= 1.0){
+         timer1Count += (uint16_t)timerCycleCounter[0];
+         timerCycleCounter[0] -= (uint16_t)timerCycleCounter[0];
       }
 
       if(timer1OldCount < timer1Compare && timer1Count >= timer1Compare){
@@ -141,6 +141,7 @@ static inline void timer12Clk32(){
 
          //set timer triggered bit
          registerArrayWrite16(TSTAT1, registerArrayRead16(TSTAT1) | 0x0001);
+         timerStatusReadAcknowledge[0] &= 0xFFFE;//lock bit until next read
 
          if(!(timer1Control & 0x0100)){
             //not free running, reset to 0, to prevent loss of ticks after compare event just subtract timerXCompare
@@ -163,22 +164,22 @@ static inline void timer12Clk32(){
 
          case 0x0001://SYSCLK / timer prescaler
             if(pllIsOn())
-               timer2CycleCounter += sysclksPerClk32() / timer2Prescaler;
+               timerCycleCounter[1] += sysclksPerClk32() / timer2Prescaler;
             break;
 
          case 0x0002://SYSCLK / 16 / timer prescaler
             if(pllIsOn())
-               timer2CycleCounter += sysclksPerClk32() / 16.0 / timer2Prescaler;
+               timerCycleCounter[1] += sysclksPerClk32() / 16.0 / timer2Prescaler;
             break;
 
          default://CLK32 / timer prescaler
-            timer2CycleCounter += 1.0 / timer2Prescaler;
+            timerCycleCounter[1] += 1.0 / timer2Prescaler;
             break;
       }
 
-      if(timer2CycleCounter >= 1.0){
-         timer2Count += (uint16_t)timer2CycleCounter;
-         timer2CycleCounter -= (uint16_t)timer2CycleCounter;
+      if(timerCycleCounter[1] >= 1.0){
+         timer2Count += (uint16_t)timerCycleCounter[1];
+         timerCycleCounter[1] -= (uint16_t)timerCycleCounter[1];
       }
 
       if(timer2OldCount < timer2Compare && timer2Count >= timer2Compare){
@@ -190,6 +191,7 @@ static inline void timer12Clk32(){
 
          //set timer triggered bit
          registerArrayWrite16(TSTAT2, registerArrayRead16(TSTAT2) | 0x0001);
+         timerStatusReadAcknowledge[1] &= 0xFFFE;//lock bit until next read
 
          if(!(timer2Control & 0x0100)){
             //not free running, reset to 0, to prevent loss of ticks after compare event just subtract timerXCompare

unimplementedFeatures.txt

@@ -21,7 +21,6 @@ interrupt control register (ICR), POL5 and edge trigger selects
 ADC7846 temperature sensors
 ADC7846 dock sensor
 some undocumented I/O might be on port e and port j
-timers shouldn't allow comp bits to be cleared until read with a 1 in them and should remain in interrupt state until they are cleared(this is unverified)
 
 Debug tools:
 missing icons
@@ -41,6 +40,7 @@ Had to modify musashi because the damn NDK isn't C compatible, m68kcpu.h, line 5
 
 
 Fixed:
+timers shouldn't allow comp bits to be cleared until read with a 1 in them and should remain in interrupt state until they are cleared(the interrupt state part is unverified)
 SED1376 byte and word swap bits
 qt play pause icon not working for emu control button
 SED1376 register access