Merge pull request #109 from SpiceWare/master

ARM Timer 1 support

src/emucore/CartDPCPlus.cxx

@@ -21,6 +21,7 @@
 #include "System.hxx"
 #include "Thumbulator.hxx"
 #include "CartDPCPlus.hxx"
+#include "TIA.hxx"
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 CartridgeDPCPlus::CartridgeDPCPlus(const uInt8* image, uInt32 size,
@@ -31,6 +32,7 @@ CartridgeDPCPlus::CartridgeDPCPlus(const uInt8* image, uInt32 size,
     myParameterPointer(0),
     mySystemCycles(0),
     myFractionalClocks(0.0),
+    myARMCycles(0),
     myCurrentBank(0)
 {
   // Store image, making sure it's at least 29KB
@@ -72,6 +74,7 @@ void CartridgeDPCPlus::reset()
 {
   // Update cycles to the current system cycles
   mySystemCycles = mySystem->cycles();
+  myARMCycles = mySystem->cycles();
   myFractionalClocks = 0.0;
 
   setInitialState();
@@ -106,6 +109,7 @@ void CartridgeDPCPlus::systemCyclesReset()
 {
   // Adjust the cycle counter so that it reflects the new value
   mySystemCycles -= mySystem->cycles();
+  myARMCycles -= mySystem->cycles();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -188,7 +192,20 @@ inline void CartridgeDPCPlus::callFunction(uInt8 value)
     case 255:
       // Call user written ARM code (most likely be C compiled for ARM)
       try {
-        myThumbEmulator->run();
+        Int32 cycles = mySystem->cycles() - myARMCycles;
+        myARMCycles = mySystem->cycles();
+        
+        // setConsoleTiming should go elsewhere for one-time-setup, but doesn't
+        // work in install()
+        //
+        // if put in setInitialState() Stella ends up crashing in System.hxx at
+        //      TIA& tia() const { return myTIA; }
+        // with error
+        //      "Thread 1: EXC_BAD_ACCESS (code=1, address=0x20)"
+        
+        myThumbEmulator->setConsoleTiming(mySystem->tia().consoleTiming());
+        
+        myThumbEmulator->run(cycles);
       }
       catch(const runtime_error& e) {
         if(!mySystem->autodetectMode())
@@ -680,8 +697,12 @@ bool CartridgeDPCPlus::save(Serializer& out) const
     // The random number generator register
     out.putInt(myRandomNumber);
 
+    // Get system cycles and fractional clocks
     out.putInt(mySystemCycles);
     out.putInt(uInt32(myFractionalClocks * 100000000.0));
+    
+    // clock info for Thumbulator
+    out.putInt(myARMCycles);
   }
   catch(...)
   {
@@ -743,6 +764,9 @@ bool CartridgeDPCPlus::load(Serializer& in)
     // Get system cycles and fractional clocks
     mySystemCycles = in.getInt();
     myFractionalClocks = double(in.getInt()) / 100000000.0;
+    
+    // clock info for Thumbulator
+    myARMCycles = (Int32)in.getInt();
   }
   catch(...)
   {

src/emucore/CartDPCPlus.hxx

@@ -260,6 +260,9 @@ class CartridgeDPCPlus : public Cartridge
     // Fractional DPC music OSC clocks unused during the last update
     double myFractionalClocks;
   
+    // System cycle count when the last Thumbulator->Run() occurred
+    Int32 myARMCycles;
+
     // Indicates which bank is currently active
     uInt16 myCurrentBank;
 

src/emucore/Thumbulator.cxx

@@ -56,8 +56,11 @@ using Common::Base;
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Thumbulator::Thumbulator(const uInt16* rom_ptr, uInt16* ram_ptr, bool traponfatal)
   : rom(rom_ptr),
-    ram(ram_ptr)
+    ram(ram_ptr),
+    T1TCR(0),
+    T1TC(0)
 {
+  setConsoleTiming(ConsoleTiming::ntsc);
   trapFatalErrors(traponfatal);
   reset();
 }
@@ -79,6 +82,43 @@ string Thumbulator::run()
   return statusMsg.str();
 }
 
+void Thumbulator::setConsoleTiming(ConsoleTiming timing)
+{
+  // this sets how many ticks of the Harmony/Melody clock
+  // will occur per tick of the 6507 clock
+  constexpr double NTSC   = 70.0 / 1.193182;  // NTSC  6507 clock rate
+  constexpr double PAL    = 70.0 / 1.182298;  // PAL   6507 clock rate
+  constexpr double SECAM  = 70.0 / 1.187500;  // SECAM 6507 clock rate
+  
+  switch (timing)
+  {
+    case ConsoleTiming::ntsc:   timing_factor = NTSC;   break;
+    case ConsoleTiming::secam:  timing_factor = SECAM;  break;
+    case ConsoleTiming::pal:    timing_factor = PAL;    break;
+    default:                    timing_factor = NTSC;   break;
+  }
+}
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void Thumbulator::updateTimer(uInt32 cycles)
+{
+  double increment;
+  
+  increment = cycles * timing_factor;
+  
+  if (T1TCR & 1) // bit 0 controls timer on/off
+  {
+    
+    T1TC += uInt32(increment);
+  }
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+string Thumbulator::run(uInt32 cycles)
+{
+  updateTimer(cycles);
+  return this->run();
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 inline int Thumbulator::fatalError(const char* opcode, uInt32 v1, const char* msg)
 {
@@ -236,6 +276,14 @@ void Thumbulator::write32(uInt32 addr, uInt32 data)
           DO_DISS(statusMsg << "uart: [" << char(data&0xFF) << "]" << endl);
           break;
           
+        case 0xE0008004:  // T1TCR - Timer 1 Control Register
+          T1TCR = data;
+          break;
+          
+        case 0xE0008008:  // T1TC - Timer 1 Counter
+          T1TC = data;
+          break;
+
         case 0xE000E010:
         {
           uInt32 old = systick_ctrl;
@@ -348,6 +396,14 @@ uInt32 Thumbulator::read32(uInt32 addr)
     {
       switch(addr)
       {
+        case 0xE0008004:  // T1TCR - Timer 1 Control Register
+          data = T1TCR;
+          return data;
+          
+        case 0xE0008008:  // T1TC - Timer 1 Counter
+          data = T1TC;
+          return data;
+          
         case 0xE000E010:
           data = systick_ctrl;
           systick_ctrl &= (~0x00010000);

src/emucore/Thumbulator.hxx

@@ -28,6 +28,7 @@
 #define THUMBULATOR_HXX
 
 #include "bspf.hxx"
+#include "Console.hxx"
 
 #define ROMADDMASK 0x7FFF
 #define RAMADDMASK 0x1FFF
@@ -54,6 +55,7 @@ class Thumbulator
                otherwise an empty string
     */
     string run();
+    string run(uInt32 cycles);
 
     /**
       Normally when a fatal error is encountered, the ARM emulation
@@ -69,6 +71,8 @@ class Thumbulator
     */
     static void trapFatalErrors(bool enable) { trapOnFatal = enable; }
   
+  void setConsoleTiming(ConsoleTiming timing);
+
   private:
     uInt32 read_register(uInt32 reg);
     void write_register(uInt32 reg, uInt32 data);
@@ -78,6 +82,7 @@ class Thumbulator
     uInt32 read32(uInt32 addr);
     void write16(uInt32 addr, uInt32 data);
     void write32(uInt32 addr, uInt32 data);
+    void updateTimer(uInt32 cycles);
 
     void do_zflag(uInt32 x);
     void do_nflag(uInt32 x);
@@ -107,6 +112,13 @@ class Thumbulator
     uInt32 systick_ctrl, systick_reload, systick_count, systick_calibrate;
     uInt64 instructions, fetches, reads, writes, systick_ints;
   
+    // For emulation of LPC2103's timer 1, used for NTSC/PAL/SECAM detection.
+    // Register names from documentation:
+    // http://www.nxp.com/documents/user_manual/UM10161.pdf
+    uInt32 T1TCR;  // Timer 1 Timer Control Register
+    uInt32 T1TC;   // Timer 1 Timer Counter
+    double timing_factor;
+
     ostringstream statusMsg;
 
     static bool trapOnFatal;