Shamusworld >> Repos - virtualjaguar/blob - src/jerry.cpp

   1 //
   2 // JERRY Core
   3 //
   4 // Originally by David Raingeard
   5 // GCC/SDL port by Niels Wagenaar (Linux/WIN32) and Carwin Jones (BeOS)
   6 // Cleanups/rewrites/fixes by James Hammons
   7 //
   8 // JLH = James Hammons <jlhamm@acm.org>
   9 //
  10 // WHO  WHEN        WHAT
  11 // ---  ----------  -----------------------------------------------------------
  12 // JLH  11/25/2009  Major rewrite of memory subsystem and handlers
  13 //
  14
  15 // ------------------------------------------------------------
  16 // JERRY REGISTERS (Mapped by Aaron Giles)
  17 // ------------------------------------------------------------
  18 // F10000-F13FFF   R/W   xxxxxxxx xxxxxxxx   Jerry
  19 // F10000            W   xxxxxxxx xxxxxxxx   JPIT1 - timer 1 pre-scaler
  20 // F10002            W   xxxxxxxx xxxxxxxx   JPIT2 - timer 1 divider
  21 // F10004            W   xxxxxxxx xxxxxxxx   JPIT3 - timer 2 pre-scaler
  22 // F10008            W   xxxxxxxx xxxxxxxx   JPIT4 - timer 2 divider
  23 // F10010            W   ------xx xxxxxxxx   CLK1 - processor clock divider
  24 // F10012            W   ------xx xxxxxxxx   CLK2 - video clock divider
  25 // F10014            W   -------- --xxxxxx   CLK3 - chroma clock divider
  26 // F10020          R/W   ---xxxxx ---xxxxx   JINTCTRL - interrupt control register
  27 //                   W   ---x---- --------      (J_SYNCLR - clear synchronous serial intf ints)
  28 //                   W   ----x--- --------      (J_ASYNCLR - clear asynchronous serial intf ints)
  29 //                   W   -----x-- --------      (J_TIM2CLR - clear timer 2 [tempo] interrupts)
  30 //                   W   ------x- --------      (J_TIM1CLR - clear timer 1 [sample] interrupts)
  31 //                   W   -------x --------      (J_EXTCLR - clear external interrupts)
  32 //                 R/W   -------- ---x----      (J_SYNENA - enable synchronous serial intf ints)
  33 //                 R/W   -------- ----x---      (J_ASYNENA - enable asynchronous serial intf ints)
  34 //                 R/W   -------- -----x--      (J_TIM2ENA - enable timer 2 [tempo] interrupts)
  35 //                 R/W   -------- ------x-      (J_TIM1ENA - enable timer 1 [sample] interrupts)
  36 //                 R/W   -------- -------x      (J_EXTENA - enable external interrupts)
  37 // F10030          R/W   -------- xxxxxxxx   ASIDATA - asynchronous serial data
  38 // F10032            W   -x------ -xxxxxxx   ASICTRL - asynchronous serial control
  39 //                   W   -x------ --------      (TXBRK - transmit break)
  40 //                   W   -------- -x------      (CLRERR - clear error)
  41 //                   W   -------- --x-----      (RINTEN - enable receiver interrupts)
  42 //                   W   -------- ---x----      (TINTEN - enable transmitter interrupts)
  43 //                   W   -------- ----x---      (RXIPOL - receiver input polarity)
  44 //                   W   -------- -----x--      (TXOPOL - transmitter output polarity)
  45 //                   W   -------- ------x-      (PAREN - parity enable)
  46 //                   W   -------- -------x      (ODD - odd parity select)
  47 // F10032          R     xxx-xxxx x-xxxxxx   ASISTAT - asynchronous serial status
  48 //                 R     x------- --------      (ERROR - OR of PE,FE,OE)
  49 //                 R     -x------ --------      (TXBRK - transmit break)
  50 //                 R     --x----- --------      (SERIN - serial input)
  51 //                 R     ----x--- --------      (OE - overrun error)
  52 //                 R     -----x-- --------      (FE - framing error)
  53 //                 R     ------x- --------      (PE - parity error)
  54 //                 R     -------x --------      (TBE - transmit buffer empty)
  55 //                 R     -------- x-------      (RBF - receive buffer full)
  56 //                 R     -------- ---x----      (TINTEN - enable transmitter interrupts)
  57 //                 R     -------- ----x---      (RXIPOL - receiver input polarity)
  58 //                 R     -------- -----x--      (TXOPOL - transmitter output polarity)
  59 //                 R     -------- ------x-      (PAREN - parity enable)
  60 //                 R     -------- -------x      (ODD - odd parity)
  61 // F10034          R/W   xxxxxxxx xxxxxxxx   ASICLK - asynchronous serial interface clock
  62 // F10036          R     xxxxxxxx xxxxxxxx   JPIT1 - timer 1 pre-scaler
  63 // F10038          R     xxxxxxxx xxxxxxxx   JPIT2 - timer 1 divider
  64 // F1003A          R     xxxxxxxx xxxxxxxx   JPIT3 - timer 2 pre-scaler
  65 // F1003C          R     xxxxxxxx xxxxxxxx   JPIT4 - timer 2 divider
  66 // ------------------------------------------------------------
  67 // F14000-F17FFF   R/W   xxxxxxxx xxxxxxxx   Joysticks and GPIO0-5
  68 // F14000          R     xxxxxxxx xxxxxxxx   JOYSTICK - read joystick state
  69 // F14000            W   x------- xxxxxxxx   JOYSTICK - latch joystick output
  70 //                   W   x------- --------      (enable joystick outputs)
  71 //                   W   -------- xxxxxxxx      (joystick output data)
  72 // F14002          R     xxxxxxxx xxxxxxxx   JOYBUTS - button register
  73 // F14800-F14FFF   R/W   xxxxxxxx xxxxxxxx   GPI00 - reserved (CD-ROM? no.)
  74 // F15000-F15FFF   R/W   xxxxxxxx xxxxxxxx   GPI01 - reserved
  75 // F16000-F16FFF   R/W   xxxxxxxx xxxxxxxx   GPI02 - reserved
  76 // F17000-F177FF   R/W   xxxxxxxx xxxxxxxx   GPI03 - reserved
  77 // F17800-F17BFF   R/W   xxxxxxxx xxxxxxxx   GPI04 - reserved
  78 // F17C00-F17FFF   R/W   xxxxxxxx xxxxxxxx   GPI05 - reserved
  79 // ------------------------------------------------------------
  80 // F18000-F1FFFF   R/W   xxxxxxxx xxxxxxxx   Jerry DSP
  81 // F1A100          R/W   xxxxxxxx xxxxxxxx   D_FLAGS - DSP flags register
  82 //                 R/W   x------- --------      (DMAEN - DMA enable)
  83 //                 R/W   -x------ --------      (REGPAGE - register page)
  84 //                   W   --x----- --------      (D_EXT0CLR - clear external interrupt 0)
  85 //                   W   ---x---- --------      (D_TIM2CLR - clear timer 2 interrupt)
  86 //                   W   ----x--- --------      (D_TIM1CLR - clear timer 1 interrupt)
  87 //                   W   -----x-- --------      (D_I2SCLR - clear I2S interrupt)
  88 //                   W   ------x- --------      (D_CPUCLR - clear CPU interrupt)
  89 //                 R/W   -------x --------      (D_EXT0ENA - enable external interrupt 0)
  90 //                 R/W   -------- x-------      (D_TIM2ENA - enable timer 2 interrupt)
  91 //                 R/W   -------- -x------      (D_TIM1ENA - enable timer 1 interrupt)
  92 //                 R/W   -------- --x-----      (D_I2SENA - enable I2S interrupt)
  93 //                 R/W   -------- ---x----      (D_CPUENA - enable CPU interrupt)
  94 //                 R/W   -------- ----x---      (IMASK - interrupt mask)
  95 //                 R/W   -------- -----x--      (NEGA_FLAG - ALU negative)
  96 //                 R/W   -------- ------x-      (CARRY_FLAG - ALU carry)
  97 //                 R/W   -------- -------x      (ZERO_FLAG - ALU zero)
  98 // F1A102          R/W   -------- ------xx   D_FLAGS - upper DSP flags
  99 //                 R/W   -------- ------x-      (D_EXT1ENA - enable external interrupt 1)
 100 //                 R/W   -------- -------x      (D_EXT1CLR - clear external interrupt 1)
 101 // F1A104            W   -------- ----xxxx   D_MTXC - matrix control register
 102 //                   W   -------- ----x---      (MATCOL - column/row major)
 103 //                   W   -------- -----xxx      (MATRIX3-15 - matrix width)
 104 // F1A108            W   ----xxxx xxxxxx--   D_MTXA - matrix address register
 105 // F1A10C            W   -------- -----x-x   D_END - data organization register
 106 //                   W   -------- -----x--      (BIG_INST - big endian instruction fetch)
 107 //                   W   -------- -------x      (BIG_IO - big endian I/O)
 108 // F1A110          R/W   xxxxxxxx xxxxxxxx   D_PC - DSP program counter
 109 // F1A114          R/W   xxxxxxxx xx-xxxxx   D_CTRL - DSP control/status register
 110 //                 R     xxxx---- --------      (VERSION - DSP version code)
 111 //                 R/W   ----x--- --------      (BUS_HOG - hog the bus!)
 112 //                 R/W   -----x-- --------      (D_EXT0LAT - external interrupt 0 latch)
 113 //                 R/W   ------x- --------      (D_TIM2LAT - timer 2 interrupt latch)
 114 //                 R/W   -------x --------      (D_TIM1LAT - timer 1 interrupt latch)
 115 //                 R/W   -------- x-------      (D_I2SLAT - I2S interrupt latch)
 116 //                 R/W   -------- -x------      (D_CPULAT - CPU interrupt latch)
 117 //                 R/W   -------- ---x----      (SINGLE_GO - single step one instruction)
 118 //                 R/W   -------- ----x---      (SINGLE_STEP - single step mode)
 119 //                 R/W   -------- -----x--      (FORCEINT0 - cause interrupt 0 on GPU)
 120 //                 R/W   -------- ------x-      (CPUINT - send GPU interrupt to CPU)
 121 //                 R/W   -------- -------x      (DSPGO - enable DSP execution)
 122 // F1A116          R/W   -------- -------x   D_CTRL - upper DSP control/status register
 123 //                 R/W   -------- -------x      (D_EXT1LAT - external interrupt 1 latch)
 124 // F1A118-F1A11B     W   xxxxxxxx xxxxxxxx   D_MOD - modulo instruction mask
 125 // F1A11C-F1A11F   R     xxxxxxxx xxxxxxxx   D_REMAIN - divide unit remainder
 126 // F1A11C            W   -------- -------x   D_DIVCTRL - divide unit control
 127 //                   W   -------- -------x      (DIV_OFFSET - 1=16.16 divide, 0=32-bit divide)
 128 // F1A120-F1A123   R     xxxxxxxx xxxxxxxx   D_MACHI - multiply & accumulate high bits
 129 // F1A148            W   xxxxxxxx xxxxxxxx   R_DAC - right transmit data
 130 // F1A14C            W   xxxxxxxx xxxxxxxx   L_DAC - left transmit data
 131 // F1A150            W   -------- xxxxxxxx   SCLK - serial clock frequency
 132 // F1A150          R     -------- ------xx   SSTAT
 133 //                 R     -------- ------x-      (left - no description)
 134 //                 R     -------- -------x      (WS - word strobe status)
 135 // F1A154            W   -------- --xxxx-x   SMODE - serial mode
 136 //                   W   -------- --x-----      (EVERYWORD - interrupt on MSB of every word)
 137 //                   W   -------- ---x----      (FALLING - interrupt on falling edge)
 138 //                   W   -------- ----x---      (RISING - interrupt of rising edge)
 139 //                   W   -------- -----x--      (WSEN - enable word strobes)
 140 //                   W   -------- -------x      (INTERNAL - enables serial clock)
 141 // ------------------------------------------------------------
 142 // F1B000-F1CFFF   R/W   xxxxxxxx xxxxxxxx   Local DSP RAM
 143 // ------------------------------------------------------------
 144 // F1D000          R     xxxxxxxx xxxxxxxx   ROM_TRI - triangle wave
 145 // F1D200          R     xxxxxxxx xxxxxxxx   ROM_SINE - full sine wave
 146 // F1D400          R     xxxxxxxx xxxxxxxx   ROM_AMSINE - amplitude modulated sine wave
 147 // F1D600          R     xxxxxxxx xxxxxxxx   ROM_12W - sine wave and second order harmonic
 148 // F1D800          R     xxxxxxxx xxxxxxxx   ROM_CHIRP16 - chirp
 149 // F1DA00          R     xxxxxxxx xxxxxxxx   ROM_NTRI - traingle wave with noise
 150 // F1DC00          R     xxxxxxxx xxxxxxxx   ROM_DELTA - spike
 151 // F1DE00          R     xxxxxxxx xxxxxxxx   ROM_NOISE - white noise
 152 // ------------------------------------------------------------
 153
 154 #include "jerry.h"
 155
 156 #include <string.h>                                                             // For memcpy
 157 //#include <math.h>
 158 #include "cdrom.h"
 159 #include "dac.h"
 160 #include "dsp.h"
 161 #include "eeprom.h"
 162 #include "event.h"
 163 #include "jaguar.h"
 164 #include "joystick.h"
 165 #include "log.h"
 166 #include "m68k.h"
 167 #include "settings.h"
 168 #include "tom.h"
 169 //#include "memory.h"
 170 #include "wavetable.h"
 171
 172 //Note that 44100 Hz requires samples every 22.675737 usec.
 173 #define NEW_TIMER_SYSTEM
 174 //#define JERRY_DEBUG
 175
 176 /*static*/ uint8 jerry_ram_8[0x10000];
 177
 178 //#define JERRY_CONFIG  0x4002                                          // ??? What's this ???
 179
 180 uint8 analog_x, analog_y;
 181
 182 static uint32 JERRYPIT1Prescaler;
 183 static uint32 JERRYPIT1Divider;
 184 static uint32 JERRYPIT2Prescaler;
 185 static uint32 JERRYPIT2Divider;
 186 static int32 jerry_timer_1_counter;
 187 static int32 jerry_timer_2_counter;
 188
 189 uint32 JERRYI2SInterruptDivide = 8;
 190 int32 JERRYI2SInterruptTimer = -1;
 191 uint32 jerryI2SCycles;
 192 uint32 jerryIntPending;
 193
 194 static uint16 jerryInterruptMask = 0;
 195 static uint16 jerryPendingInterrupt = 0;
 196 // Private function prototypes
 197
 198 void JERRYResetPIT1(void);
 199 void JERRYResetPIT2(void);
 200 void JERRYResetI2S(void);
 201
 202 void JERRYPIT1Callback(void);
 203 void JERRYPIT2Callback(void);
 204 void JERRYI2SCallback(void);
 205
 206 //This approach is probably wrong, since the timer is continuously counting down, though
 207 //it might only be a problem if the # of interrupts generated is greater than 1--the M68K's
 208 //timeslice should be running during that phase... (The DSP needs to be aware of this!)
 209
 210 //This is only used by the old system, so once the new timer system is working this
 211 //should be safe to nuke.
 212 void JERRYI2SExec(uint32 cycles)
 213 {
 214 #ifndef NEW_TIMER_SYSTEM
 215 #warning "externed var in source--should be in header file. !!! FIX !!!"
 216         extern uint16 serialMode;                                               // From DAC.CPP
 217         if (serialMode & 0x01)                                                  // INTERNAL flag (JERRY is master)
 218         {
 219
 220         // Why is it called this? Instead of SCLK? Shouldn't this be read from DAC.CPP???
 221 //Yes, it should. !!! FIX !!!
 222                 JERRYI2SInterruptDivide &= 0xFF;
 223
 224                 if (JERRYI2SInterruptTimer == -1)
 225                 {
 226                 // We don't have to divide the RISC clock rate by this--the reason is a bit
 227                 // convoluted. Will put explanation here later...
 228 // What's needed here is to find the ratio of the frequency to the number of clock cycles
 229 // in one second. For example, if the sample rate is 44100, we divide the clock rate by
 230 // this: 26590906 / 44100 = 602 cycles.
 231 // Which means, every 602 cycles that go by we have to generate an interrupt.
 232                         jerryI2SCycles = 32 * (2 * (JERRYI2SInterruptDivide + 1));
 233                 }
 234
 235                 JERYI2SInterruptTimer -= cycles;
 236                 if (JERRYI2SInterruptTimer <= 0)
 237                 {
 238 //This is probably wrong as well (i.e., need to check enable lines)... !!! FIX !!!
 239                         DSPSetIRQLine(DSPIRQ_SSI, ASSERT_LINE);
 240                         JERRYI2SInterruptTimer += jerryI2SCycles;
 241 #ifdef JERRY_DEBUG
 242                         if (JERRYI2SInterruptTimer < 0)
 243                                 WriteLog("JERRY: Missed generating an interrupt (missed %u)!\n", (-JERRYI2SInterruptTimer / jerryI2SCycles) + 1);
 244 #endif
 245                 }
 246         }
 247         else                                                                                    // JERRY is slave to external word clock
 248         {
 249                 // This is just a temporary kludge to see if the CD bus mastering works
 250                 // I.e., this is totally faked...!
 251 // The whole interrupt system is pretty much borked and is need of an overhaul.
 252 // What we need is a way of handling these interrupts when they happen instead of
 253 // scanline boundaries the way it is now.
 254                 JERRYI2SInterruptTimer -= cycles;
 255                 if (JERRYI2SInterruptTimer <= 0)
 256                 {
 257 //This is probably wrong as well (i.e., need to check enable lines)... !!! FIX !!! [DONE]
 258                         if (ButchIsReadyToSend())//Not sure this is right spot to check...
 259                         {
 260 //      return GetWordFromButchSSI(offset, who);
 261                                 SetSSIWordsXmittedFromButch();
 262                                 DSPSetIRQLine(DSPIRQ_SSI, ASSERT_LINE);
 263                         }
 264                         JERRYI2SInterruptTimer += 602;
 265                 }
 266         }
 267 #else
 268         RemoveCallback(JERRYI2SCallback);
 269         JERRYI2SCallback();
 270 #endif
 271 }
 272
 273 //NOTE: This is only used by the old execution core. Safe to nuke once it's stable.
 274 void JERRYExecPIT(uint32 cycles)
 275 {
 276 //This is wrong too: Counters are *always* spinning! !!! FIX !!! [DONE]
 277 //      if (jerry_timer_1_counter)
 278                 jerry_timer_1_counter -= cycles;
 279
 280         if (jerry_timer_1_counter <= 0)
 281         {
 282 //Also, it can generate a CPU interrupt as well... !!! FIX !!! or does it? Maybe it goes Timer->GPU->CPU?
 283                 DSPSetIRQLine(DSPIRQ_TIMER0, ASSERT_LINE);      // This does the 'IRQ enabled' checking...
 284 //              JERRYResetPIT1();
 285                 jerry_timer_1_counter += (JERRYPIT1Prescaler + 1) * (JERRYPIT1Divider + 1);
 286         }
 287
 288 //This is wrong too: Counters are *always* spinning! !!! FIX !!! [DONE]
 289 //      if (jerry_timer_2_counter)
 290                 jerry_timer_2_counter -= cycles;
 291
 292         if (jerry_timer_2_counter <= 0)
 293         {
 294 //Also, it can generate a CPU interrupt as well... !!! FIX !!! or does it? Maybe it goes Timer->GPU->CPU?
 295                 DSPSetIRQLine(DSPIRQ_TIMER1, ASSERT_LINE);      // This does the 'IRQ enabled' checking...
 296 //              JERRYResetPIT2();
 297                 jerry_timer_2_counter += (JERRYPIT2Prescaler + 1) * (JERRYPIT2Divider + 1);
 298         }
 299 }
 300
 301 void JERRYResetI2S(void)
 302 {
 303         //WriteLog("i2s: reseting\n");
 304 //This is really SCLK... !!! FIX !!!
 305         JERRYI2SInterruptDivide = 8;
 306         JERRYI2SInterruptTimer = -1;
 307 }
 308
 309 void JERRYResetPIT1(void)
 310 {
 311 #ifndef NEW_TIMER_SYSTEM
 312 /*      if (!JERRYPIT1Prescaler || !JERRYPIT1Divider)
 313                 jerry_timer_1_counter = 0;
 314         else//*/
 315 //Small problem with this approach: Overflow if both are = $FFFF. !!! FIX !!!
 316                 jerry_timer_1_counter = (JERRYPIT1Prescaler + 1) * (JERRYPIT1Divider + 1);
 317
 318 //      if (jerry_timer_1_counter)
 319 //              WriteLog("jerry: reseting timer 1 to 0x%.8x (%i)\n",jerry_timer_1_counter,jerry_timer_1_counter);
 320
 321 #else
 322         RemoveCallback(JERRYPIT1Callback);
 323
 324         if (JERRYPIT1Prescaler | JERRYPIT1Divider)
 325         {
 326                 double usecs = (float)(JERRYPIT1Prescaler + 1) * (float)(JERRYPIT1Divider + 1) * RISC_CYCLE_IN_USEC;
 327                 SetCallbackTime(JERRYPIT1Callback, usecs);
 328         }
 329 #endif
 330 }
 331
 332 void JERRYResetPIT2(void)
 333 {
 334 #ifndef NEW_TIMER_SYSTEM
 335 /*      if (!JERRYPIT2Prescaler || !JERRYPIT2Divider)
 336         {
 337                 jerry_timer_2_counter = 0;
 338                 return;
 339         }
 340         else//*/
 341                 jerry_timer_2_counter = (JERRYPIT2Prescaler + 1) * (JERRYPIT2Divider + 1);
 342
 343 //      if (jerry_timer_2_counter)
 344 //              WriteLog("jerry: reseting timer 2 to 0x%.8x (%i)\n",jerry_timer_2_counter,jerry_timer_2_counter);
 345
 346 #else
 347         RemoveCallback(JERRYPIT2Callback);
 348
 349         if (JERRYPIT1Prescaler | JERRYPIT1Divider)
 350         {
 351                 double usecs = (float)(JERRYPIT2Prescaler + 1) * (float)(JERRYPIT2Divider + 1) * RISC_CYCLE_IN_USEC;
 352                 SetCallbackTime(JERRYPIT2Callback, usecs);
 353         }
 354 #endif
 355 }
 356
 357 // This is the cause of the regressions in Cybermorph and Missile Command 3D...
 358 // Solution: Probably have to check the DSP enable bit before sending these thru.
 359 //#define JERRY_NO_IRQS
 360 void JERRYPIT1Callback(void)
 361 {
 362 #ifndef JERRY_NO_IRQS
 363 //WriteLog("JERRY: In PIT1 callback, IRQM=$%04X\n", jerryInterruptMask);
 364         if (TOMIRQEnabled(IRQ_DSP))
 365         {
 366                 if (jerryInterruptMask & IRQ2_TIMER1)           // CPU Timer 1 IRQ
 367                 {
 368 // Not sure, but I think we don't generate another IRQ if one's already going...
 369 // But this seems to work... :-/
 370                         jerryPendingInterrupt |= IRQ2_TIMER1;
 371                         m68k_set_irq(2);                                                // Generate 68K IPL 2
 372                 }
 373         }
 374 #endif
 375
 376         DSPSetIRQLine(DSPIRQ_TIMER0, ASSERT_LINE);      // This does the 'IRQ enabled' checking...
 377         JERRYResetPIT1();
 378 }
 379
 380 void JERRYPIT2Callback(void)
 381 {
 382 #ifndef JERRY_NO_IRQS
 383         if (TOMIRQEnabled(IRQ_DSP))
 384         {
 385 //WriteLog("JERRY: In PIT2 callback, IRQM=$%04X\n", jerryInterruptMask);
 386                 if (jerryInterruptMask & IRQ2_TIMER2)           // CPU Timer 2 IRQ
 387                 {
 388                         jerryPendingInterrupt |= IRQ2_TIMER2;
 389                         m68k_set_irq(2);                                                // Generate 68K IPL 2
 390                 }
 391         }
 392 #endif
 393
 394         DSPSetIRQLine(DSPIRQ_TIMER1, ASSERT_LINE);      // This does the 'IRQ enabled' checking...
 395         JERRYResetPIT2();
 396 }
 397
 398 void JERRYI2SCallback(void)
 399 {
 400         // Why is it called this? Instead of SCLK? Shouldn't this be read from DAC.CPP???
 401 //Yes, it should. !!! FIX !!!
 402 #warning "Why is it called this? Instead of SCLK? Shouldn't this be read from DAC.CPP??? Yes, it should. !!! FIX !!!"
 403         JERRYI2SInterruptDivide &= 0xFF;
 404         // We don't have to divide the RISC clock rate by this--the reason is a bit
 405         // convoluted. Will put explanation here later...
 406 // What's needed here is to find the ratio of the frequency to the number of clock cycles
 407 // in one second. For example, if the sample rate is 44100, we divide the clock rate by
 408 // this: 26590906 / 44100 = 602 cycles.
 409 // Which means, every 602 cycles that go by we have to generate an interrupt.
 410         jerryI2SCycles = 32 * (2 * (JERRYI2SInterruptDivide + 1));
 411
 412 //This should be in this file with an extern reference in the header file so that
 413 //DAC.CPP can see it... !!! FIX !!!
 414         extern uint16 serialMode;                                               // From DAC.CPP
 415
 416         if (serialMode & 0x01)                                                  // INTERNAL flag (JERRY is master)
 417         {
 418                 DSPSetIRQLine(DSPIRQ_SSI, ASSERT_LINE);         // This does the 'IRQ enabled' checking...
 419                 double usecs = (float)jerryI2SCycles * RISC_CYCLE_IN_USEC;
 420                 SetCallbackTime(JERRYI2SCallback, usecs);
 421         }
 422         else                                                                                    // JERRY is slave to external word clock
 423         {
 424 //Note that 44100 Hz requires samples every 22.675737 usec.
 425 //When JERRY is slave to the word clock, we need to do interrupts either at 44.1K
 426 //sample rate or at a 88.2K sample rate (11.332... usec).
 427 /*              // This is just a temporary kludge to see if the CD bus mastering works
 428                 // I.e., this is totally faked...!
 429 // The whole interrupt system is pretty much borked and is need of an overhaul.
 430 // What we need is a way of handling these interrupts when they happen instead of
 431 // scanline boundaries the way it is now.
 432                 jerry_i2s_interrupt_timer -= cycles;
 433                 if (jerry_i2s_interrupt_timer <= 0)
 434                 {
 435 //This is probably wrong as well (i.e., need to check enable lines)... !!! FIX !!! [DONE]
 436                         if (ButchIsReadyToSend())//Not sure this is right spot to check...
 437                         {
 438 //      return GetWordFromButchSSI(offset, who);
 439                                 SetSSIWordsXmittedFromButch();
 440                                 DSPSetIRQLine(DSPIRQ_SSI, ASSERT_LINE);
 441                         }
 442                         jerry_i2s_interrupt_timer += 602;
 443                 }*/
 444
 445                 if (ButchIsReadyToSend())//Not sure this is right spot to check...
 446                 {
 447 //      return GetWordFromButchSSI(offset, who);
 448                         SetSSIWordsXmittedFromButch();
 449                         DSPSetIRQLine(DSPIRQ_SSI, ASSERT_LINE);
 450                 }
 451
 452                 SetCallbackTime(JERRYI2SCallback, 22.675737);
 453         }
 454 }
 455
 456
 457 void JERRYInit(void)
 458 {
 459         JoystickInit();
 460         DACInit();
 461         memcpy(&jerry_ram_8[0xD000], waveTableROM, 0x1000);
 462
 463         JERRYPIT1Prescaler = 0xFFFF;
 464         JERRYPIT2Prescaler = 0xFFFF;
 465         JERRYPIT1Divider = 0xFFFF;
 466         JERRYPIT2Divider = 0xFFFF;
 467         jerryInterruptMask = 0x0000;
 468         jerryPendingInterrupt = 0x0000;
 469 }
 470
 471 void JERRYReset(void)
 472 {
 473         JoystickReset();
 474         EepromReset();
 475         JERRYResetI2S();
 476         DACReset();
 477
 478         memset(jerry_ram_8, 0x00, 0xD000);              // Don't clear out the Wavetable ROM...!
 479         JERRYPIT1Prescaler = 0xFFFF;
 480         JERRYPIT2Prescaler = 0xFFFF;
 481         JERRYPIT1Divider = 0xFFFF;
 482         JERRYPIT2Divider = 0xFFFF;
 483         jerry_timer_1_counter = 0;
 484         jerry_timer_2_counter = 0;
 485         jerryInterruptMask = 0x0000;
 486         jerryPendingInterrupt = 0x0000;
 487 }
 488
 489 void JERRYDone(void)
 490 {
 491         WriteLog("JERRY: M68K Interrupt control ($F10020) = %04X\n", GET16(jerry_ram_8, 0x20));
 492         JoystickDone();
 493         DACDone();
 494         EepromDone();
 495 }
 496
 497 bool JERRYIRQEnabled(int irq)
 498 {
 499         // Read the word @ $F10020
 500 //      return jerry_ram_8[0x21] & (1 << irq);
 501         return jerryInterruptMask & irq;
 502 }
 503
 504 void JERRYSetPendingIRQ(int irq)
 505 {
 506         // This is the shadow of INT (it's a split RO/WO register)
 507 //      jerryIntPending |= (1 << irq);
 508         jerryPendingInterrupt |= irq;
 509 }
 510
 511 //
 512 // JERRY byte access (read)
 513 //
 514 uint8 JERRYReadByte(uint32 offset, uint32 who/*=UNKNOWN*/)
 515 {
 516 #ifdef JERRY_DEBUG
 517         WriteLog("JERRY: Reading byte at %06X\n", offset);
 518 #endif
 519         if ((offset >= DSP_CONTROL_RAM_BASE) && (offset < DSP_CONTROL_RAM_BASE+0x20))
 520                 return DSPReadByte(offset, who);
 521         else if ((offset >= DSP_WORK_RAM_BASE) && (offset < DSP_WORK_RAM_BASE+0x2000))
 522                 return DSPReadByte(offset, who);
 523         // LRXD/RRXD/SSTAT $F1A148/4C/50 (really 16-bit registers...)
 524         else if (offset >= 0xF1A148 && offset <= 0xF1A153)
 525                 return DACReadByte(offset, who);
 526 //      F10036          R     xxxxxxxx xxxxxxxx   JPIT1 - timer 1 pre-scaler
 527 //      F10038          R     xxxxxxxx xxxxxxxx   JPIT2 - timer 1 divider
 528 //      F1003A          R     xxxxxxxx xxxxxxxx   JPIT3 - timer 2 pre-scaler
 529 //      F1003C          R     xxxxxxxx xxxxxxxx   JPIT4 - timer 2 divider
 530 //This is WRONG!
 531 //      else if (offset >= 0xF10000 && offset <= 0xF10007)
 532 //This is still wrong. What needs to be returned here are the values being counted down
 533 //in the jerry_timer_n_counter variables... !!! FIX !!! [DONE]
 534
 535 //This is probably the problem with the new timer code... This is invalid
 536 //under the new system... !!! FIX !!!
 537         else if ((offset >= 0xF10036) && (offset <= 0xF1003D))
 538         {
 539 #ifndef NEW_TIMER_SYSTEM
 540 //              jerry_timer_1_counter = (JERRYPIT1Prescaler + 1) * (JERRYPIT1Divider + 1);
 541                 uint32 counter1Hi = (jerry_timer_1_counter / (JERRYPIT1Divider + 1)) - 1;
 542                 uint32 counter1Lo = (jerry_timer_1_counter % (JERRYPIT1Divider + 1)) - 1;
 543                 uint32 counter2Hi = (jerry_timer_2_counter / (JERRYPIT2Divider + 1)) - 1;
 544                 uint32 counter2Lo = (jerry_timer_2_counter % (JERRYPIT2Divider + 1)) - 1;
 545
 546                 switch(offset & 0x0F)
 547                 {
 548                 case 6:
 549 //                      return JERRYPIT1Prescaler >> 8;
 550                         return counter1Hi >> 8;
 551                 case 7:
 552 //                      return JERRYPIT1Prescaler & 0xFF;
 553                         return counter1Hi & 0xFF;
 554                 case 8:
 555 //                      return JERRYPIT1Divider >> 8;
 556                         return counter1Lo >> 8;
 557                 case 9:
 558 //                      return JERRYPIT1Divider & 0xFF;
 559                         return counter1Lo & 0xFF;
 560                 case 10:
 561 //                      return JERRYPIT2Prescaler >> 8;
 562                         return counter2Hi >> 8;
 563                 case 11:
 564 //                      return JERRYPIT2Prescaler & 0xFF;
 565                         return counter2Hi & 0xFF;
 566                 case 12:
 567 //                      return JERRYPIT2Divider >> 8;
 568                         return counter2Lo >> 8;
 569                 case 13:
 570 //                      return JERRYPIT2Divider & 0xFF;
 571                         return counter2Lo & 0xFF;
 572                 }
 573 #else
 574 WriteLog("JERRY: Unhandled timer read (BYTE) at %08X...\n", offset);
 575 #endif
 576         }
 577 //      else if (offset >= 0xF10010 && offset <= 0xF10015)
 578 //              return clock_byte_read(offset);
 579 //      else if (offset >= 0xF17C00 && offset <= 0xF17C01)
 580 //              return anajoy_byte_read(offset);
 581         else if (offset >= 0xF14000 && offset <= 0xF14003)
 582                 return JoystickReadByte(offset) | EepromReadByte(offset);
 583         else if (offset >= 0xF14000 && offset <= 0xF1A0FF)
 584                 return EepromReadByte(offset);
 585
 586         return jerry_ram_8[offset & 0xFFFF];
 587 }
 588
 589 //
 590 // JERRY word access (read)
 591 //
 592 uint16 JERRYReadWord(uint32 offset, uint32 who/*=UNKNOWN*/)
 593 {
 594 #ifdef JERRY_DEBUG
 595         WriteLog("JERRY: Reading word at %06X\n", offset);
 596 #endif
 597
 598         if ((offset >= DSP_CONTROL_RAM_BASE) && (offset < DSP_CONTROL_RAM_BASE+0x20))
 599                 return DSPReadWord(offset, who);
 600         else if (offset >= DSP_WORK_RAM_BASE && offset <= DSP_WORK_RAM_BASE + 0x1FFF)
 601                 return DSPReadWord(offset, who);
 602         // LRXD/RRXD/SSTAT $F1A148/4C/50 (really 16-bit registers...)
 603         else if (offset >= 0xF1A148 && offset <= 0xF1A153)
 604                 return DACReadWord(offset, who);
 605 //      F10036          R     xxxxxxxx xxxxxxxx   JPIT1 - timer 1 pre-scaler
 606 //      F10038          R     xxxxxxxx xxxxxxxx   JPIT2 - timer 1 divider
 607 //      F1003A          R     xxxxxxxx xxxxxxxx   JPIT3 - timer 2 pre-scaler
 608 //      F1003C          R     xxxxxxxx xxxxxxxx   JPIT4 - timer 2 divider
 609 //This is WRONG!
 610 //      else if ((offset >= 0xF10000) && (offset <= 0xF10007))
 611 //This is still wrong. What needs to be returned here are the values being counted down
 612 //in the jerry_timer_n_counter variables... !!! FIX !!! [DONE]
 613         else if ((offset >= 0xF10036) && (offset <= 0xF1003D))
 614         {
 615 #ifndef NEW_TIMER_SYSTEM
 616 //              jerry_timer_1_counter = (JERRYPIT1Prescaler + 1) * (JERRYPIT1Divider + 1);
 617                 uint32 counter1Hi = (jerry_timer_1_counter / (JERRYPIT1Divider + 1)) - 1;
 618                 uint32 counter1Lo = (jerry_timer_1_counter % (JERRYPIT1Divider + 1)) - 1;
 619                 uint32 counter2Hi = (jerry_timer_2_counter / (JERRYPIT2Divider + 1)) - 1;
 620                 uint32 counter2Lo = (jerry_timer_2_counter % (JERRYPIT2Divider + 1)) - 1;
 621
 622                 switch(offset & 0x0F)
 623                 {
 624                 case 6:
 625 //                      return JERRYPIT1Prescaler;
 626                         return counter1Hi;
 627                 case 8:
 628 //                      return JERRYPIT1Divider;
 629                         return counter1Lo;
 630                 case 10:
 631 //                      return JERRYPIT2Prescaler;
 632                         return counter2Hi;
 633                 case 12:
 634 //                      return JERRYPIT2Divider;
 635                         return counter2Lo;
 636                 }
 637                 // Unaligned word reads???
 638 #else
 639 WriteLog("JERRY: Unhandled timer read (WORD) at %08X...\n", offset);
 640 #endif
 641         }
 642 //      else if ((offset >= 0xF10010) && (offset <= 0xF10015))
 643 //              return clock_word_read(offset);
 644         else if (offset == 0xF10020)
 645 //              return jerryIntPending;
 646                 return jerryPendingInterrupt;
 647 //      else if ((offset >= 0xF17C00) && (offset <= 0xF17C01))
 648 //              return anajoy_word_read(offset);
 649         else if (offset == 0xF14000)
 650                 return (JoystickReadWord(offset) & 0xFFFE) | EepromReadWord(offset);
 651         else if ((offset >= 0xF14002) && (offset < 0xF14003))
 652                 return JoystickReadWord(offset);
 653         else if ((offset >= 0xF14000) && (offset <= 0xF1A0FF))
 654                 return EepromReadWord(offset);
 655
 656 /*if (offset >= 0xF1D000)
 657         WriteLog("JERRY: Reading word at %08X [%04X]...\n", offset, ((uint16)jerry_ram_8[(offset+0)&0xFFFF] << 8) | jerry_ram_8[(offset+1)&0xFFFF]);//*/
 658
 659         offset &= 0xFFFF;                               // Prevent crashing...!
 660         return ((uint16)jerry_ram_8[offset+0] << 8) | jerry_ram_8[offset+1];
 661 }
 662
 663 //
 664 // JERRY byte access (write)
 665 //
 666 void JERRYWriteByte(uint32 offset, uint8 data, uint32 who/*=UNKNOWN*/)
 667 {
 668 #ifdef JERRY_DEBUG
 669         WriteLog("jerry: writing byte %.2x at 0x%.6x\n",data,offset);
 670 #endif
 671         if ((offset >= DSP_CONTROL_RAM_BASE) && (offset < DSP_CONTROL_RAM_BASE+0x20))
 672         {
 673                 DSPWriteByte(offset, data, who);
 674                 return;
 675         }
 676         else if ((offset >= DSP_WORK_RAM_BASE) && (offset < DSP_WORK_RAM_BASE+0x2000))
 677         {
 678                 DSPWriteByte(offset, data, who);
 679                 return;
 680         }
 681         // SCLK ($F1A150--8 bits wide)
 682 //NOTE: This should be taken care of in DAC...
 683         else if ((offset >= 0xF1A152) && (offset <= 0xF1A153))
 684         {
 685 //              WriteLog("JERRY: Writing %02X to SCLK...\n", data);
 686                 if ((offset & 0x03) == 2)
 687                         JERRYI2SInterruptDivide = (JERRYI2SInterruptDivide & 0x00FF) | ((uint32)data << 8);
 688                 else
 689                         JERRYI2SInterruptDivide = (JERRYI2SInterruptDivide & 0xFF00) | (uint32)data;
 690
 691                 JERRYI2SInterruptTimer = -1;
 692 #ifndef NEW_TIMER_SYSTEM
 693                 jerry_i2s_exec(0);
 694 #else
 695                 RemoveCallback(JERRYI2SCallback);
 696                 JERRYI2SCallback();
 697 #endif
 698 //              return;
 699         }
 700         // LTXD/RTXD/SCLK/SMODE $F1A148/4C/50/54 (really 16-bit registers...)
 701         else if (offset >= 0xF1A148 && offset <= 0xF1A157)
 702         {
 703                 DACWriteByte(offset, data, who);
 704                 return;
 705         }
 706         else if (offset >= 0xF10000 && offset <= 0xF10007)
 707         {
 708 #ifndef NEW_TIMER_SYSTEM
 709                 switch (offset & 0x07)
 710                 {
 711                 case 0:
 712                         JERRYPIT1Prescaler = (JERRYPIT1Prescaler & 0x00FF) | (data << 8);
 713                         JERRYResetPIT1();
 714                         break;
 715                 case 1:
 716                         JERRYPIT1Prescaler = (JERRYPIT1Prescaler & 0xFF00) | data;
 717                         JERRYResetPIT1();
 718                         break;
 719                 case 2:
 720                         JERRYPIT1Divider = (JERRYPIT1Divider & 0x00FF) | (data << 8);
 721                         JERRYResetPIT1();
 722                         break;
 723                 case 3:
 724                         JERRYPIT1Divider = (JERRYPIT1Divider & 0xFF00) | data;
 725                         JERRYResetPIT1();
 726                         break;
 727                 case 4:
 728                         JERRYPIT2Prescaler = (JERRYPIT2Prescaler & 0x00FF) | (data << 8);
 729                         JERRYResetPIT2();
 730                         break;
 731                 case 5:
 732                         JERRYPIT2Prescaler = (JERRYPIT2Prescaler & 0xFF00) | data;
 733                         JERRYResetPIT2();
 734                         break;
 735                 case 6:
 736                         JERRYPIT2Divider = (JERRYPIT2Divider & 0x00FF) | (data << 8);
 737                         JERRYResetPIT2();
 738                         break;
 739                 case 7:
 740                         JERRYPIT2Divider = (JERRYPIT2Divider & 0xFF00) | data;
 741                         JERRYResetPIT2();
 742                 }
 743 #else
 744 WriteLog("JERRY: Unhandled timer write (BYTE) at %08X...\n", offset);
 745 #endif
 746                 return;
 747         }
 748 /*      else if ((offset >= 0xF10010) && (offset <= 0xF10015))
 749         {
 750                 clock_byte_write(offset, data);
 751                 return;
 752         }//*/
 753         // JERRY -> 68K interrupt enables/latches (need to be handled!)
 754         else if (offset >= 0xF10020 && offset <= 0xF10021)//WAS:23)
 755         {
 756                 if (offset == 0xF10020)
 757                 {
 758                         // Clear pending interrupts...
 759                         jerryPendingInterrupt &= ~data;
 760                 }
 761                 else if (offset == 0xF10021)
 762                         jerryInterruptMask = data;
 763 //WriteLog("JERRY: (68K int en/lat - Unhandled!) Tried to write $%02X to $%08X!\n", data, offset);
 764 //WriteLog("JERRY: (Previous is partially handled... IRQMask=$%04X)\n", jerryInterruptMask);
 765         }
 766 /*      else if ((offset >= 0xF17C00) && (offset <= 0xF17C01))
 767         {
 768                 anajoy_byte_write(offset, data);
 769                 return;
 770         }*/
 771         else if ((offset >= 0xF14000) && (offset <= 0xF14003))
 772         {
 773                 JoystickWriteByte(offset, data);
 774                 EepromWriteByte(offset, data);
 775                 return;
 776         }
 777         else if ((offset >= 0xF14000) && (offset <= 0xF1A0FF))
 778         {
 779                 EepromWriteByte(offset, data);
 780                 return;
 781         }
 782
 783 //Need to protect write attempts to Wavetable ROM (F1D000-FFF)
 784         if (offset >= 0xF1D000 && offset <= 0xF1DFFF)
 785                 return;
 786
 787         jerry_ram_8[offset & 0xFFFF] = data;
 788 }
 789
 790 //
 791 // JERRY word access (write)
 792 //
 793 void JERRYWriteWord(uint32 offset, uint16 data, uint32 who/*=UNKNOWN*/)
 794 {
 795 #ifdef JERRY_DEBUG
 796         WriteLog( "JERRY: Writing word %04X at %06X\n", data, offset);
 797 #endif
 798 #if 1
 799 if (offset == 0xF10000)
 800         WriteLog("JERRY: JPIT1 word written by %s: %u\n", whoName[who], data);
 801 else if (offset == 0xF10002)
 802         WriteLog("JERRY: JPIT2 word written by %s: %u\n", whoName[who], data);
 803 else if (offset == 0xF10004)
 804         WriteLog("JERRY: JPIT3 word written by %s: %u\n", whoName[who], data);
 805 else if (offset == 0xF10006)
 806         WriteLog("JERRY: JPIT4 word written by %s: %u\n", whoName[who], data);
 807 else if (offset == 0xF10010)
 808         WriteLog("JERRY: CLK1 word written by %s: %u\n", whoName[who], data);
 809 else if (offset == 0xF10012)
 810         WriteLog("JERRY: CLK2 word written by %s: %u\n", whoName[who], data);
 811 else if (offset == 0xF10014)
 812         WriteLog("JERRY: CLK3 word written by %s: %u\n", whoName[who], data);
 813 //else if (offset == 0xF1A100)
 814 //      WriteLog("JERRY: D_FLAGS word written by %s: %u\n", whoName[who], data);
 815 //else if (offset == 0xF1A102)
 816 //      WriteLog("JERRY: D_FLAGS+2 word written by %s: %u\n", whoName[who], data);
 817 else if (offset == 0xF10020)
 818         WriteLog("JERRY: JINTCTRL word written by %s: $%04X (%s%s%s%s%s%s)\n", whoName[who], data,
 819                 (data & 0x01 ? "Extrnl " : ""), (data & 0x02 ? "DSP " : ""),
 820                 (data & 0x04 ? "Timer0 " : ""), (data & 0x08 ? "Timer1 " : ""),
 821                 (data & 0x10 ? "ASI " : ""), (data & 0x20 ? "I2S " : ""));
 822 #endif
 823
 824         if ((offset >= DSP_CONTROL_RAM_BASE) && (offset < DSP_CONTROL_RAM_BASE+0x20))
 825         {
 826                 DSPWriteWord(offset, data, who);
 827                 return;
 828         }
 829         else if ((offset >= DSP_WORK_RAM_BASE) && (offset < DSP_WORK_RAM_BASE+0x2000))
 830         {
 831                 DSPWriteWord(offset, data, who);
 832                 return;
 833         }
 834 //NOTE: This should be taken care of in DAC...
 835         else if (offset == 0xF1A152)                                    // Bottom half of SCLK ($F1A150)
 836         {
 837                 WriteLog("JERRY: Writing $%X to SCLK (by %s)...\n", data, whoName[who]);
 838 //This should *only* be enabled when SMODE has its INTERNAL bit set! !!! FIX !!!
 839                 JERRYI2SInterruptDivide = (uint8)data;
 840                 JERRYI2SInterruptTimer = -1;
 841 #ifndef NEW_TIMER_SYSTEM
 842                 jerry_i2s_exec(0);
 843 #else
 844                 RemoveCallback(JERRYI2SCallback);
 845                 JERRYI2SCallback();
 846 #endif
 847
 848                 DACWriteWord(offset, data, who);
 849                 return;
 850         }
 851         // LTXD/RTXD/SCLK/SMODE $F1A148/4C/50/54 (really 16-bit registers...)
 852         else if (offset >= 0xF1A148 && offset <= 0xF1A156)
 853         {
 854                 DACWriteWord(offset, data, who);
 855                 return;
 856         }
 857         else if (offset >= 0xF10000 && offset <= 0xF10007)
 858         {
 859 //#ifndef NEW_TIMER_SYSTEM
 860 #if 1
 861                 switch(offset & 0x07)
 862                 {
 863                 case 0:
 864                         JERRYPIT1Prescaler = data;
 865                         JERRYResetPIT1();
 866                         break;
 867                 case 2:
 868                         JERRYPIT1Divider = data;
 869                         JERRYResetPIT1();
 870                         break;
 871                 case 4:
 872                         JERRYPIT2Prescaler = data;
 873                         JERRYResetPIT2();
 874                         break;
 875                 case 6:
 876                         JERRYPIT2Divider = data;
 877                         JERRYResetPIT2();
 878                 }
 879                 // Need to handle (unaligned) cases???
 880 #else
 881 WriteLog("JERRY: Unhandled timer write %04X (WORD) at %08X by %s...\n", data, offset, whoName[who]);
 882 #endif
 883                 return;
 884         }
 885 /*      else if (offset >= 0xF10010 && offset < 0xF10016)
 886         {
 887                 clock_word_write(offset, data);
 888                 return;
 889         }//*/
 890         // JERRY -> 68K interrupt enables/latches (need to be handled!)
 891         else if (offset >= 0xF10020 && offset <= 0xF10022)
 892         {
 893                 jerryInterruptMask = data & 0xFF;
 894                 jerryPendingInterrupt &= ~(data >> 8);
 895 //WriteLog("JERRY: (68K int en/lat - Unhandled!) Tried to write $%04X to $%08X!\n", data, offset);
 896 //WriteLog("JERRY: (Previous is partially handled... IRQMask=$%04X)\n", jerryInterruptMask);
 897                 return;
 898         }
 899 /*      else if (offset >= 0xF17C00 && offset < 0xF17C02)
 900         {
 901 //I think this was removed from the Jaguar. If so, then we don't need this...!
 902                 anajoy_word_write(offset, data);
 903                 return;
 904         }*/
 905         else if (offset >= 0xF14000 && offset < 0xF14003)
 906         {
 907                 JoystickWriteWord(offset, data);
 908                 EepromWriteWord(offset, data);
 909                 return;
 910         }
 911         else if (offset >= 0xF14000 && offset <= 0xF1A0FF)
 912         {
 913                 EepromWriteWord(offset, data);
 914                 return;
 915         }
 916
 917 //Need to protect write attempts to Wavetable ROM (F1D000-FFF)
 918         if (offset >= 0xF1D000 && offset <= 0xF1DFFF)
 919                 return;
 920
 921         jerry_ram_8[(offset+0) & 0xFFFF] = (data >> 8) & 0xFF;
 922         jerry_ram_8[(offset+1) & 0xFFFF] = data & 0xFF;
 923 }
 924
 925 int JERRYGetPIT1Frequency(void)
 926 {
 927         int systemClockFrequency = (vjs.hardwareTypeNTSC ? RISC_CLOCK_RATE_NTSC : RISC_CLOCK_RATE_PAL);
 928         return systemClockFrequency / ((JERRYPIT1Prescaler + 1) * (JERRYPIT1Divider + 1));
 929 }
 930
 931 int JERRYGetPIT2Frequency(void)
 932 {
 933         int systemClockFrequency = (vjs.hardwareTypeNTSC ? RISC_CLOCK_RATE_NTSC : RISC_CLOCK_RATE_PAL);
 934         return systemClockFrequency / ((JERRYPIT2Prescaler + 1) * (JERRYPIT2Divider + 1));
 935 }