//
// DAC (really, Synchronous Serial Interface) Handler
//
-// by cal2
+// Originally by David Raingeard
// GCC/SDL port by Niels Wagenaar (Linux/WIN32) and Caz (BeOS)
// Rewritten by James L. Hammons
//
-#include <SDL.h>
+#include "SDL.h"
+#include "m68k.h"
#include "jaguar.h"
-#include "dac.h"
#include "settings.h"
+#include "dac.h"
//#define DEBUG_DAC
-#define BUFFER_SIZE 0x8000 // Make the DAC buffers 32K x 16 bits
+#define BUFFER_SIZE 0x10000 // Make the DAC buffers 64K x 16 bits
// Jaguar memory locations
#define LTXD 0xF1A148
#define RTXD 0xF1A14C
+#define LRXD 0xF1A148
+#define RRXD 0xF1A14C
#define SCLK 0xF1A150
#define SMODE 0xF1A154
+// Global variables
+
+uint16 lrxd, rrxd; // I2S ports (into Jaguar)
+
// Local variables
-uint32 LeftFIFOHeadPtr, LeftFIFOTailPtr, RightFIFOHeadPtr, RightFIFOTailPtr;
-SDL_AudioSpec desired;
+static uint32 LeftFIFOHeadPtr, LeftFIFOTailPtr, RightFIFOHeadPtr, RightFIFOTailPtr;
+static SDL_AudioSpec desired;
+static bool SDLSoundInitialized = false;
// We can get away with using native endian here because we can tell SDL to use the native
// endian when looking at the sample buffer, i.e., no need to worry about it.
-uint16 * DACBuffer;
-uint8 SCLKFrequencyDivider = 19; // Default is roughly 22 KHz (20774 Hz in NTSC mode)
-uint16 serialMode = 0;
+static uint16 * DACBuffer;
+static uint8 SCLKFrequencyDivider = 19; // Default is roughly 22 KHz (20774 Hz in NTSC mode)
+/*static*/ uint16 serialMode = 0;
// Private function prototypes
int GetCalculatedFrequency(void);
//
-// Initialize the SDL sound system (?) (!)
+// Initialize the SDL sound system
//
void DACInit(void)
{
desired.freq = GetCalculatedFrequency(); // SDL will do conversion on the fly, if it can't get the exact rate. Nice!
desired.format = AUDIO_S16SYS; // This uses the native endian (for portability)...
desired.channels = 2;
- desired.samples = 4096; // Let's try a 4K buffer (can always go lower)
+// desired.samples = 4096; // Let's try a 4K buffer (can always go lower)
+ desired.samples = 2048; // Let's try a 2K buffer (can always go lower)
desired.callback = SDLSoundCallback;
if (SDL_OpenAudio(&desired, NULL) < 0) // NULL means SDL guarantees what we want
{
- WriteLog("DAC: Failed to initialize SDL sound. Shutting down!\n");
- log_done();
- exit(1);
+// WriteLog("DAC: Failed to initialize SDL sound. Shutting down!\n");
+// log_done();
+// exit(1);
+ WriteLog("DAC: Failed to initialize SDL sound...\n");
+ }
+ else
+ {
+ SDLSoundInitialized = true;
+ DACReset();
+ SDL_PauseAudio(false); // Start playback!
+ WriteLog("DAC: Successfully initialized.\n");
}
-
- DACReset();
- SDL_PauseAudio(false); // Start playback!
- WriteLog("DAC: Successfully initialized.\n");
}
//
}
//
-// Close down the SDL sound subsystem (?) (!)
+// Close down the SDL sound subsystem
//
void DACDone(void)
{
- SDL_PauseAudio(true);
- SDL_CloseAudio();
+ if (SDLSoundInitialized)
+ {
+ SDL_PauseAudio(true);
+ SDL_CloseAudio();
+ }
+
+ memory_free(DACBuffer);
WriteLog("DAC: Done.\n");
}
// Actually, it's a bit more involved than this, but this is the general idea:
// memcpy(buffer, DACBuffer, length);
for(int i=0; i<numSamplesReady; i++)
- // Could also use (as long as BUFFER_SIZE is a multiple of 2):
((uint16 *)buffer)[i] = DACBuffer[(LeftFIFOHeadPtr + i) % BUFFER_SIZE];
+ // Could also use (as long as BUFFER_SIZE is a multiple of 2):
// buffer[i] = DACBuffer[(LeftFIFOHeadPtr + i) & (BUFFER_SIZE - 1)];
LeftFIFOHeadPtr = (LeftFIFOHeadPtr + numSamplesReady) % BUFFER_SIZE;
RightFIFOHeadPtr = (RightFIFOHeadPtr + numSamplesReady) % BUFFER_SIZE;
// Could also use (as long as BUFFER_SIZE is a multiple of 2):
-// LeftFIFOHeadPtr = (LeftFIFOHeadPtr + (numSamplesReady)) & (BUFFER_SIZE - 1);
-// RightFIFOHeadPtr = (RightFIFOHeadPtr + (numSamplesReady)) & (BUFFER_SIZE - 1);
+// LeftFIFOHeadPtr = (LeftFIFOHeadPtr + numSamplesReady) & (BUFFER_SIZE - 1);
+// RightFIFOHeadPtr = (RightFIFOHeadPtr + numSamplesReady) & (BUFFER_SIZE - 1);
//WriteLog(" -> Left/RightFIFOHeadPtr: %u/%u, Left/RightFIFOTailPtr: %u/%u\n", LeftFIFOHeadPtr, RightFIFOHeadPtr, LeftFIFOTailPtr, RightFIFOTailPtr);
}
//Hmm. Seems that the SDL buffer isn't being starved by the DAC buffer...
//
int GetCalculatedFrequency(void)
{
-// extern bool hardwareTypeNTSC;
int systemClockFrequency = (vjs.hardwareTypeNTSC ? RISC_CLOCK_RATE_NTSC : RISC_CLOCK_RATE_PAL);
// We divide by 32 here in order to find the frequency of 32 SCLKs in a row (transferring
//
// LTXD/RTXD/SCLK/SMODE ($F1A148/4C/50/54)
//
-void DACWriteByte(uint32 offset, uint8 data)
+void DACWriteByte(uint32 offset, uint8 data, uint32 who/*= UNKNOWN*/)
{
- WriteLog("DAC: Writing %02X at %08X\n", data, offset);
+ WriteLog("DAC: %s writing BYTE %02X at %08X\n", whoName[who], data, offset);
if (offset == SCLK + 3)
DACWriteWord(offset - 3, (uint16)data);
}
-void DACWriteWord(uint32 offset, uint16 data)
+void DACWriteWord(uint32 offset, uint16 data, uint32 who/*= UNKNOWN*/)
{
if (offset == LTXD + 2)
{
- if (LeftFIFOTailPtr + 2 != LeftFIFOHeadPtr)
- {
- SDL_LockAudio(); // Is it necessary to do this? Mebbe.
- // We use a circular buffer 'cause it's easy. Note that the callback function
- // takes care of dumping audio to the soundcard...! Also note that we're writing
- // the samples in the buffer in an interleaved L/R format.
- LeftFIFOTailPtr = (LeftFIFOTailPtr + 2) % BUFFER_SIZE;
- DACBuffer[LeftFIFOTailPtr] = data;
-// Aaron's code does this, but I don't know why...
-//Flipping this bit makes the audio MUCH louder. Need to look at the amplitude of the
-//waveform to see if any massaging is needed here...
-//Looks like a cheap & dirty way to convert signed samples to unsigned...
-// DACBuffer[LeftFIFOTailPtr] = data ^ 0x8000;
- SDL_UnlockAudio();
- }
-#ifdef DEBUG_DAC
- else
- WriteLog("DAC: Ran into FIFO's left tail pointer!\n");
-#endif
+ // Spin until buffer has been drained (for too fast processors!)...
+//Small problem--if Head == 0 and Tail == buffer end, then this will fail... !!! FIX !!!
+//[DONE]
+ // Also, we're taking advantage of the fact that the buffer is a multiple of two
+ // in this check...
+ while ((LeftFIFOTailPtr + 2) & (BUFFER_SIZE - 1) == LeftFIFOHeadPtr);
+
+ SDL_LockAudio(); // Is it necessary to do this? Mebbe.
+ // We use a circular buffer 'cause it's easy. Note that the callback function
+ // takes care of dumping audio to the soundcard...! Also note that we're writing
+ // the samples in the buffer in an interleaved L/R format.
+ LeftFIFOTailPtr = (LeftFIFOTailPtr + 2) % BUFFER_SIZE;
+ DACBuffer[LeftFIFOTailPtr] = data;
+ SDL_UnlockAudio();
}
else if (offset == RTXD + 2)
{
- if (RightFIFOTailPtr + 2 != RightFIFOHeadPtr)
- {
- SDL_LockAudio();
- RightFIFOTailPtr = (RightFIFOTailPtr + 2) % BUFFER_SIZE;
- DACBuffer[RightFIFOTailPtr] = data;
-// Aaron's code does this, but I don't know why...
-// DACBuffer[RightFIFOTailPtr] = data ^ 0x8000;
- SDL_UnlockAudio();
- }
-#ifdef DEBUG_DAC
+ // Spin until buffer has been drained (for too fast processors!)...
+//uint32 spin = 0;
+ while ((RightFIFOTailPtr + 2) & (BUFFER_SIZE - 1) == RightFIFOHeadPtr);
+/* {
+spin++;
+if (spin == 0x10000000)
+{
+ WriteLog("\nStuck in right DAC spinlock! Tail=%u, Head=%u\nAborting!\n", RightFIFOTailPtr, RightFIFOHeadPtr);
+ log_done();
+ exit(0);
+}
+ }*/
+
+//This is wrong if (RightFIFOTailPtr + 2 != RightFIFOHeadPtr)
+// {
+ SDL_LockAudio();
+ RightFIFOTailPtr = (RightFIFOTailPtr + 2) % BUFFER_SIZE;
+ DACBuffer[RightFIFOTailPtr] = data;
+ SDL_UnlockAudio();
+// }
+/*#ifdef DEBUG_DAC
else
WriteLog("DAC: Ran into FIFO's right tail pointer!\n");
-#endif
+#endif*/
}
else if (offset == SCLK + 2) // Sample rate
{
//Of course a better way would be to query the hardware to find the upper limit...
if (data > 7) // Anything less than 8 is too high!
{
- SDL_CloseAudio();
+ if (SDLSoundInitialized)
+ SDL_CloseAudio();
+
desired.freq = GetCalculatedFrequency();// SDL will do conversion on the fly, if it can't get the exact rate. Nice!
WriteLog("DAC: Changing sample rate to %u Hz!\n", desired.freq);
- if (SDL_OpenAudio(&desired, NULL) < 0) // NULL means SDL guarantees what we want
+ if (SDLSoundInitialized)
{
- WriteLog("DAC: Failed to initialize SDL sound: %s.\nDesired freq: %u\nShutting down!\n", SDL_GetError(), desired.freq);
- log_done();
- exit(1);
+ if (SDL_OpenAudio(&desired, NULL) < 0) // NULL means SDL guarantees what we want
+ {
+ WriteLog("DAC: Failed to initialize SDL sound: %s.\nDesired freq: %u\nShutting down!\n", SDL_GetError(), desired.freq);
+ log_done();
+ exit(1);
+ }
}
DACReset();
- SDL_PauseAudio(false); // Start playback!
+
+ if (SDLSoundInitialized)
+ SDL_PauseAudio(false); // Start playback!
}
}
}
else if (offset == SMODE + 2)
{
serialMode = data;
- WriteLog("DAC: Writing to SMODE. Bits: %s%s%s%s%s%s\n",
+ WriteLog("DAC: %s writing to SMODE. Bits: %s%s%s%s%s%s [68K PC=%08X]\n", whoName[who],
(data & 0x01 ? "INTERNAL " : ""), (data & 0x02 ? "MODE " : ""),
(data & 0x04 ? "WSEN " : ""), (data & 0x08 ? "RISING " : ""),
- (data & 0x10 ? "FALLING " : ""), (data & 0x20 ? "EVERYWORD" : ""));
+ (data & 0x10 ? "FALLING " : ""), (data & 0x20 ? "EVERYWORD" : ""),
+ m68k_get_reg(NULL, M68K_REG_PC));
}
}
//
// LRXD/RRXD/SSTAT ($F1A148/4C/50)
//
-uint8 DACReadByte(uint32 offset)
+uint8 DACReadByte(uint32 offset, uint32 who/*= UNKNOWN*/)
{
-// WriteLog("DAC: Reading byte from %08X\n", offset);
+// WriteLog("DAC: %s reading byte from %08X\n", whoName[who], offset);
return 0xFF;
}
-uint16 DACReadWord(uint32 offset)
+//static uint16 fakeWord = 0;
+uint16 DACReadWord(uint32 offset, uint32 who/*= UNKNOWN*/)
{
-// WriteLog("DAC: Reading word from %08X\n", offset);
- return 0xFFFF;
+// WriteLog("DAC: %s reading word from %08X\n", whoName[who], offset);
+// return 0xFFFF;
+// WriteLog("DAC: %s reading WORD %04X from %08X\n", whoName[who], fakeWord, offset);
+// return fakeWord++;
+//NOTE: This only works if a bunch of things are set in BUTCH which we currently don't
+// check for. !!! FIX !!!
+// Partially fixed: We check for I2SCNTRL in the JERRY I2S routine...
+// return GetWordFromButchSSI(offset, who);
+ if (offset == LRXD || offset == RRXD)
+ return 0x0000;
+ else if (offset == LRXD + 2)
+ return lrxd;
+ else if (offset == RRXD + 2)
+ return rrxd;
+
+ return 0xFFFF; // May need SSTAT as well... (but may be a Jaguar II only feature)
}