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Diffstat (limited to 'src/mame/audio/snes.c')
-rw-r--r-- | src/mame/audio/snes.c | 1348 |
1 files changed, 1348 insertions, 0 deletions
diff --git a/src/mame/audio/snes.c b/src/mame/audio/snes.c new file mode 100644 index 00000000000..8b7a8b78446 --- /dev/null +++ b/src/mame/audio/snes.c @@ -0,0 +1,1348 @@ +/*************************************************************************** + + snes.c + + File to handle the sound emulation of the Nintendo Super NES. + + By R. Belmont, adapted from OpenSPC 0.3.99 by Brad Martin with permission. + Thanks to Brad and also to Charles Bilyu? of SNeESe. + + OpenSPC's license terms (the LGPL) follow: + + --------------------------------------------------------------------------- + + Copyright (c) 2003-2005 Brad Martin. + + OpenSPC is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + OpenSPC 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 Lesser General Public License for more details. + +***************************************************************************/ + +#include <math.h> +#include "driver.h" +#include "streams.h" +#include "includes/snes.h" + +static struct +{ + UINT8 enabled; + UINT16 counter; + emu_timer *timer; +} timers[3]; +static sound_stream *channel; +static UINT8 DSPregs[256]; /* DSP registers */ +static UINT8 snes_ipl_region[64]; /* SPC top 64 bytes */ + +static const int gauss[]= +{ + 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, + 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, + 0x001, 0x001, 0x001, 0x001, 0x001, 0x001, 0x001, 0x001, + 0x001, 0x001, 0x001, 0x002, 0x002, 0x002, 0x002, 0x002, + 0x002, 0x002, 0x003, 0x003, 0x003, 0x003, 0x003, 0x004, + 0x004, 0x004, 0x004, 0x004, 0x005, 0x005, 0x005, 0x005, + 0x006, 0x006, 0x006, 0x006, 0x007, 0x007, 0x007, 0x008, + 0x008, 0x008, 0x009, 0x009, 0x009, 0x00A, 0x00A, 0x00A, + 0x00B, 0x00B, 0x00B, 0x00C, 0x00C, 0x00D, 0x00D, 0x00E, + 0x00E, 0x00F, 0x00F, 0x00F, 0x010, 0x010, 0x011, 0x011, + 0x012, 0x013, 0x013, 0x014, 0x014, 0x015, 0x015, 0x016, + 0x017, 0x017, 0x018, 0x018, 0x019, 0x01A, 0x01B, 0x01B, + 0x01C, 0x01D, 0x01D, 0x01E, 0x01F, 0x020, 0x020, 0x021, + 0x022, 0x023, 0x024, 0x024, 0x025, 0x026, 0x027, 0x028, + 0x029, 0x02A, 0x02B, 0x02C, 0x02D, 0x02E, 0x02F, 0x030, + 0x031, 0x032, 0x033, 0x034, 0x035, 0x036, 0x037, 0x038, + 0x03A, 0x03B, 0x03C, 0x03D, 0x03E, 0x040, 0x041, 0x042, + 0x043, 0x045, 0x046, 0x047, 0x049, 0x04A, 0x04C, 0x04D, + 0x04E, 0x050, 0x051, 0x053, 0x054, 0x056, 0x057, 0x059, + 0x05A, 0x05C, 0x05E, 0x05F, 0x061, 0x063, 0x064, 0x066, + 0x068, 0x06A, 0x06B, 0x06D, 0x06F, 0x071, 0x073, 0x075, + 0x076, 0x078, 0x07A, 0x07C, 0x07E, 0x080, 0x082, 0x084, + 0x086, 0x089, 0x08B, 0x08D, 0x08F, 0x091, 0x093, 0x096, + 0x098, 0x09A, 0x09C, 0x09F, 0x0A1, 0x0A3, 0x0A6, 0x0A8, + 0x0AB, 0x0AD, 0x0AF, 0x0B2, 0x0B4, 0x0B7, 0x0BA, 0x0BC, + 0x0BF, 0x0C1, 0x0C4, 0x0C7, 0x0C9, 0x0CC, 0x0CF, 0x0D2, + 0x0D4, 0x0D7, 0x0DA, 0x0DD, 0x0E0, 0x0E3, 0x0E6, 0x0E9, + 0x0EC, 0x0EF, 0x0F2, 0x0F5, 0x0F8, 0x0FB, 0x0FE, 0x101, + 0x104, 0x107, 0x10B, 0x10E, 0x111, 0x114, 0x118, 0x11B, + 0x11E, 0x122, 0x125, 0x129, 0x12C, 0x130, 0x133, 0x137, + 0x13A, 0x13E, 0x141, 0x145, 0x148, 0x14C, 0x150, 0x153, + 0x157, 0x15B, 0x15F, 0x162, 0x166, 0x16A, 0x16E, 0x172, + 0x176, 0x17A, 0x17D, 0x181, 0x185, 0x189, 0x18D, 0x191, + 0x195, 0x19A, 0x19E, 0x1A2, 0x1A6, 0x1AA, 0x1AE, 0x1B2, + 0x1B7, 0x1BB, 0x1BF, 0x1C3, 0x1C8, 0x1CC, 0x1D0, 0x1D5, + 0x1D9, 0x1DD, 0x1E2, 0x1E6, 0x1EB, 0x1EF, 0x1F3, 0x1F8, + 0x1FC, 0x201, 0x205, 0x20A, 0x20F, 0x213, 0x218, 0x21C, + 0x221, 0x226, 0x22A, 0x22F, 0x233, 0x238, 0x23D, 0x241, + 0x246, 0x24B, 0x250, 0x254, 0x259, 0x25E, 0x263, 0x267, + 0x26C, 0x271, 0x276, 0x27B, 0x280, 0x284, 0x289, 0x28E, + 0x293, 0x298, 0x29D, 0x2A2, 0x2A6, 0x2AB, 0x2B0, 0x2B5, + 0x2BA, 0x2BF, 0x2C4, 0x2C9, 0x2CE, 0x2D3, 0x2D8, 0x2DC, + 0x2E1, 0x2E6, 0x2EB, 0x2F0, 0x2F5, 0x2FA, 0x2FF, 0x304, + 0x309, 0x30E, 0x313, 0x318, 0x31D, 0x322, 0x326, 0x32B, + 0x330, 0x335, 0x33A, 0x33F, 0x344, 0x349, 0x34E, 0x353, + 0x357, 0x35C, 0x361, 0x366, 0x36B, 0x370, 0x374, 0x379, + 0x37E, 0x383, 0x388, 0x38C, 0x391, 0x396, 0x39B, 0x39F, + 0x3A4, 0x3A9, 0x3AD, 0x3B2, 0x3B7, 0x3BB, 0x3C0, 0x3C5, + 0x3C9, 0x3CE, 0x3D2, 0x3D7, 0x3DC, 0x3E0, 0x3E5, 0x3E9, + 0x3ED, 0x3F2, 0x3F6, 0x3FB, 0x3FF, 0x403, 0x408, 0x40C, + 0x410, 0x415, 0x419, 0x41D, 0x421, 0x425, 0x42A, 0x42E, + 0x432, 0x436, 0x43A, 0x43E, 0x442, 0x446, 0x44A, 0x44E, + 0x452, 0x455, 0x459, 0x45D, 0x461, 0x465, 0x468, 0x46C, + 0x470, 0x473, 0x477, 0x47A, 0x47E, 0x481, 0x485, 0x488, + 0x48C, 0x48F, 0x492, 0x496, 0x499, 0x49C, 0x49F, 0x4A2, + 0x4A6, 0x4A9, 0x4AC, 0x4AF, 0x4B2, 0x4B5, 0x4B7, 0x4BA, + 0x4BD, 0x4C0, 0x4C3, 0x4C5, 0x4C8, 0x4CB, 0x4CD, 0x4D0, + 0x4D2, 0x4D5, 0x4D7, 0x4D9, 0x4DC, 0x4DE, 0x4E0, 0x4E3, + 0x4E5, 0x4E7, 0x4E9, 0x4EB, 0x4ED, 0x4EF, 0x4F1, 0x4F3, + 0x4F5, 0x4F6, 0x4F8, 0x4FA, 0x4FB, 0x4FD, 0x4FF, 0x500, + 0x502, 0x503, 0x504, 0x506, 0x507, 0x508, 0x50A, 0x50B, + 0x50C, 0x50D, 0x50E, 0x50F, 0x510, 0x511, 0x511, 0x512, + 0x513, 0x514, 0x514, 0x515, 0x516, 0x516, 0x517, 0x517, + 0x517, 0x518, 0x518, 0x518, 0x518, 0x518, 0x519, 0x519 +}; + +/*========== DEFINES ==========*/ + +#undef DEBUG +#undef DBG_KEY +#undef DBG_ENV +#undef DBG_PMOD +#undef DBG_BRR +#undef DBG_ECHO +#undef DBG_INTRP + +#undef NO_PMOD +#undef NO_ECHO + +#define CPU_RATE ( 1024000 ) +#define SAMP_FREQ ( 32000 ) + +/*========== VARIABLES ==========*/ + +static int keyed_on; +static int keys; /* 8-bits for 8 voices */ +static voice_state_type voice_state[ 8 ]; + +/* Noise stuff */ +static int noise_cnt; +static int noise_lev; + +/* These are for the FIR echo filter */ +#ifndef NO_ECHO +static short FIRlbuf[ 8 ]; +static short FIRrbuf[ 8 ]; +static int FIRptr; +static int echo_ptr; +#endif + +/*========== CONSTANTS ==========*/ + +/* Original SPC DSP took samples 32000 times a second, which is once every + (1024000/32000 = 32) cycles. */ +static const int TS_CYC = CPU_RATE / SAMP_FREQ; + +/* Ptrs to Gaussian table */ +static const int * G1 = &gauss[ 256 ]; +static const int * G2 = &gauss[ 512 ]; +static const int * G3 = &gauss[ 255 ]; +static const int * G4 = &gauss[ -1 ]; + +static const int mask = 0xFF; + +/* This table is for envelope timing. It represents the number of counts + that should be subtracted from the counter each sample period (32kHz). + The counter starts at 30720 (0x7800). */ +static const int CNT_INIT = 0x7800; +static const int ENVCNT[ 0x20 ] + = { + 0x0000, 0x000F, 0x0014, 0x0018, 0x001E, 0x0028, 0x0030, 0x003C, + 0x0050, 0x0060, 0x0078, 0x00A0, 0x00C0, 0x00F0, 0x0140, 0x0180, + 0x01E0, 0x0280, 0x0300, 0x03C0, 0x0500, 0x0600, 0x0780, 0x0A00, + 0x0C00, 0x0F00, 0x1400, 0x1800, 0x1E00, 0x2800, 0x3C00, 0x7800 + }; + +/*========== MACROS ==========*/ + +/* Make reading the ADSR code easier */ +#define SL( v ) ( DSPregs[ ( ( v ) << 4 ) + 6 ] >> 5 ) + /* Returns SUSTAIN level */ +#define SR( v ) ( DSPregs[ ( ( v ) << 4 ) + 6 ] & 0x1F ) + /* Returns SUSTAIN rate */ + +/* Handle endianness */ +#ifndef LSB_FIRST +#define LEtoME16( x ) \ + ( ( ( ( x ) >> 8 ) & 0xFF ) | ( ( ( x ) << 8 ) & 0xFF00 ) ) +#define MEtoLE16( x ) \ + ( ( ( ( x ) >> 8 ) & 0xFF ) | ( ( ( x ) << 8 ) & 0xFF00 ) ) +#else +#define LEtoME16( x ) ( x ) +#define MEtoLE16( x ) ( x ) +#endif + +/*========== PROCEDURES ==========*/ + +static int AdvanceEnvelope /* Run envelope step & retn ENVX*/ + ( + int v /* Voice to process envelope for*/ + ); + +/* Privately shared functions (for internal library use only) */ + +/***** DSP_Reset *****/ + +void DSP_Reset /* Reset emulated DSP */ + ( void ) +{ +int i; + +#ifdef DEBUG +fprintf( stderr,"DSP_Reset\n" ); +#endif + +for( i = 0; i < 8; i++ ) + { +#ifndef NO_ECHO + FIRlbuf[ i ] = 0; + FIRrbuf[ i ] = 0; +#endif + voice_state[ i ].on_cnt = 0; + } + +#ifndef NO_ECHO +FIRptr = 0; +echo_ptr = 0; +#endif +keys = 0; +keyed_on = 0; +noise_cnt = 0; +noise_lev = 0x4000; +DSPregs[ 0x6C ] |= 0xE0; +DSPregs[ 0x4C ] = 0; +DSPregs[ 0x5C ] = 0; + +} /* DSP_Reset() */ + + +/***** DSP_Update *****/ + +void DSP_Update /* Mix one sample of audio */ + ( + short * sound_ptr /* Pointer to mix audio into */ + ) +{ +int V; +#ifndef NO_ECHO +int echo_base; +#endif +int echol; +int echor; +int envx; +int m; +int outl; +int outr; +signed long outx; /* Smpl height (must be signed) */ +src_dir_type * sd; +int v; +int vl; +voice_state_type * vp; +int vr; + +sd = ( src_dir_type * )&spc_ram[ ( int )DSPregs[ 0x5D ] << 8 ]; + +/* Check for reset */ +if( DSPregs[ 0x6C ] & 0x80 ) + { + DSP_Reset(); + } + +/* Here we check for keys on/off. Docs say that successive writes to KON/KOF + must be separated by at least 2 Ts periods or risk being neglected. + Therefore DSP only looks at these during an update, and not at the time of + the write. Only need to do this once however, since the regs haven't + changed over the whole period we need to catch up with. */ +#ifdef DBG_KEY +DSPregs[ 0x4C ] &= mask; +#endif + +/* Keying on a voice resets that bit in ENDX */ +DSPregs[ 0x7C ] &= ~DSPregs[ 0x4C ]; + +/* Question: what is the expected behavior when pitch modulation is enabled on + voice 0? Jurassic Park 2 does this. For now, using outx of zero for first + voice. */ +outx = 0; +/* Same table for noise and envelope */ +noise_cnt -= ENVCNT[ DSPregs[ 0x6C ] & 0x1F ]; +if( noise_cnt <= 0 ) + { + noise_cnt = CNT_INIT; + noise_lev = ( ( ( noise_lev << 13 ) ^ ( noise_lev << 14 ) ) & 0x4000 ) + | ( noise_lev >> 1 ); + } +outl = 0; +outr = 0; +echol = 0; +echor = 0; +for( v = 0, m = 1, V = 0; v < 8; v++, V += 16, m <<= 1 ) + { + vp = &voice_state[ v ]; + if( vp->on_cnt && ( --vp->on_cnt == 0 ) ) + { + /* Voice was keyed on */ + keys |= m; + keyed_on |= m; + vl = DSPregs[ ( v<<4 ) + 4 ]; + vp->samp_id = *( UINT32 * )&sd[ vl ]; + vp->mem_ptr = LEtoME16( sd[ vl ].vptr ); + +#ifdef DBG_KEY + fprintf( + stderr, + "Keying on voice %d, samp=0x%04X (0x%02X)\n", + v, + vp->mem_ptr, + vl + ); +#endif + + vp->header_cnt = 0; + vp->half = 0; + vp->envx = 0; + vp->end = 0; + vp->sampptr = 0; + vp->mixfrac = 3 * 4096; + + /* NOTE: Real SNES does *not* appear to initialize the envelope + counter to anything in particular. The first cycle always seems to + come at a random time sooner than expected; as yet, I have been + unable to find any pattern. I doubt it will matter though, so + we'll go ahead and do the full time for now. */ + vp->envcnt = CNT_INIT; + vp->envstate = ATTACK; + } + + if( DSPregs[ 0x4C ] & m & ~DSPregs[ 0x5C ] ) + { + /* Voice doesn't come on if key off is set */ + DSPregs[ 0x4C ] &= ~m; + vp->on_cnt = 8; + +#ifdef DBG_KEY + fprintf( stderr, "Key on set for voice %d\n", v ); +#endif + } + + if( keys & DSPregs[ 0x5C ] & m ) + { + /* Voice was keyed off */ + vp->envstate = RELEASE; + vp->on_cnt = 0; + +#ifdef DBG_KEY + fprintf( stderr, "Keying off voice %d\n", v ); +#endif + } + + if( !( keys & m & mask ) || ( ( envx = AdvanceEnvelope( v ) ) < 0 ) ) + { + DSPregs[ V + 8 ] = 0; + DSPregs[ V + 9 ] = 0; + outx = 0; + continue; + } + + vp->pitch = LEtoME16( *( ( UINT16 * )&DSPregs[ V + 2 ] ) ) + & 0x3FFF; + +#ifndef NO_PMOD + /* Pitch mod uses OUTX from last voice for this one. Luckily we haven't + modified OUTX since it was used for last voice. */ + if(DSPregs[ 0x2D ] & m ) + { +#ifdef DBG_PMOD + fprintf( + stderr, + "Pitch Modulating voice %d, outx=%ld, old pitch=%d, ", + v, + outx, + vp->pitch + ); +#endif + vp->pitch = ( vp->pitch * ( outx + 32768 ) ) >> 15; + } +#endif + +#ifdef DBG_PMOD + fprintf( stderr, "pitch=%d\n", vp->pitch ); +#endif + + for( ; vp->mixfrac >= 0; vp->mixfrac -= 4096 ) + { + /* This part performs the BRR decode 'on-the-fly'. This is more + correct than the old way, which could be fooled if the data and/or + the loop point changed while the sample was playing, or if the BRR + decode didn't produce the same result every loop because of the + filters. The event interface still has no chance of keeping up + with those kinds of tricks, though. */ + if( !vp->header_cnt ) + { + if( vp->end & 1 ) + { + /* Docs say ENDX bit is set when decode of block with source + end flag set is done. Does this apply to looping samples? + Some info I've seen suggests yes. */ + DSPregs[ 0x7C ] |= m; + if( vp->end & 2 ) + { + vp->mem_ptr = LEtoME16( sd[ DSPregs[ V + 4 ] ].lptr ); + +#ifdef DBG_BRR + fprintf( + stderr, + "BRR looping to 0x%04X\n", + vp->mem_ptr + ); +#endif + } + else + { +#ifdef DBG_KEY + fprintf( stderr, "BRR decode end, voice %d\n", v ); +#endif + + keys &= ~m; + DSPregs[ V + 8 ] = 0; + vp->envx = 0; + while( vp->mixfrac >= 0 ) + { + vp->sampbuf[ vp->sampptr ] = 0; + outx = 0; + vp->sampptr = ( vp->sampptr + 1 ) & 3; + vp->mixfrac -= 4096; + } + break; + } + } + vp->header_cnt = 8; + vl = ( UINT8 )spc_ram[ vp->mem_ptr++ ]; + vp->range = vl >> 4; + vp->end = vl & 3; + vp->filter = ( vl & 12 ) >> 2; + +#ifdef DBG_BRR + fprintf( + stderr, + "V%d: header read, range=%d, end=%d, filter=%d\n", + v, + vp->range, + vp->end, + vp->filter + ); +#endif + } + if( vp->half == 0 ) + { + vp->half = 1; + outx = ( ( signed char )spc_ram[ vp->mem_ptr ] ) >> 4; + } + else + { + vp->half = 0; + /* Funkiness to get 4-bit signed to carry through */ + outx = ( signed char )( spc_ram[ vp->mem_ptr++ ] << 4 ); + outx >>= 4; + vp->header_cnt--; + } + +#ifdef DBG_BRR + fprintf( + stderr, + "V%d: nybble=%X, ptr=%04X, smp1=%d, smp2=%d\n", + v, + outx & 0xF, + vp->mem_ptr, + vp->smp1, + vp->smp2 + ); +#endif + + /* For invalid ranges (D,E,F): if the nybble is negative, the result + is F000. If positive, 0000. Nothing else like previous range, + etc. seems to have any effect. If range is valid, do the shift + normally. Note these are both shifted right once to do the filters + properly, but the output will be shifted back again at the end. */ + if( vp->range <= 0xC ) + { + outx = ( outx << vp->range ) >> 1; + } + else + { + outx &= ~0x7FF; + +#ifdef DBG_BRR + fprintf( stderr, "V%d: invalid range! (%X)\n", v, vp->range ); +#endif + } + +#ifdef DBG_BRR + fprintf( + stderr, + "V%d: shifted delta=%04X\n", + v, + ( UINT16 )outx + ); +#endif + + switch( vp->filter ) + { + case 0: + break; + + case 1: + outx += ( vp->smp1 >> 1 ) + ( ( -vp->smp1 ) >> 5 ); + break; + + case 2: + outx += vp->smp1 + + ( ( -( vp->smp1 + ( vp->smp1 >> 1 ) ) ) >> 5 ) + - ( vp->smp2 >> 1 ) + ( vp->smp2 >> 5 ); + break; + + case 3: + outx += vp->smp1 + + ( ( -( vp->smp1 + ( vp->smp1 << 2 ) + + ( vp->smp1 << 3 ) ) ) >> 7 ) + - ( vp->smp2 >> 1 ) + + ( ( vp->smp2 + ( vp->smp2 >> 1 ) ) >> 4 ); + break; + } + + if( outx < ( signed short )0x8000 ) + { + outx = ( signed short )0x8000; + } + else if( outx > ( signed short )0x7FFF ) + { + outx = ( signed short )0x7FFF; + } + +#ifdef DBG_BRR + fprintf( + stderr, + "V%d: filter + delta=%04X\n", + v, + ( UINT16 )outx + ); +#endif + + vp->smp2 = ( signed short )vp->smp1; + vp->smp1 = ( signed short )( outx << 1 ); + vp->sampbuf[ vp->sampptr ] = vp->smp1; + +#ifdef DBG_BRR + fprintf( + stderr, + "V%d: final output: %04X\n", + v, + vp->sampbuf[ vp->sampptr ] + ); +#endif + + vp->sampptr = ( vp->sampptr + 1 ) & 3; + } + + if(DSPregs[ 0x3D ] & m ) + { +#ifdef DBG_PMOD + fprintf( stderr, "Noise enabled, voice %d\n", v ); +#endif + outx = ( signed short )( noise_lev << 1 ); + } + else + { + /* Perform 4-Point Gaussian interpolation. Take an approximation of a + Gaussian bell-curve, and move it through the sample data at a rate + determined by the pitch. The sample output at any given time is + the sum of the products of each input sample point with the value + of the bell-curve corresponding to that point. */ + vl = vp->mixfrac >> 4; + vr = ( ( G4[ -vl ] * vp->sampbuf[ vp->sampptr ] ) >> 11 ) & ~1; + vr += ( ( G3[ -vl ] + * vp->sampbuf[ ( vp->sampptr + 1 ) & 3 ] ) >> 11 ) & ~1; + vr += ( ( G2[ vl ] + * vp->sampbuf[ ( vp->sampptr + 2 ) & 3 ] ) >> 11 ) & ~1; + + /* This is to do the wrapping properly. Based on my tests with the + SNES, it appears clipping is done only if it is the fourth addition + that would cause a wrap. If it has already wrapped before the + fourth addition, it is not clipped. */ + vr = ( signed short )vr; + vr += ( ( G1[ vl ] + * vp->sampbuf[ ( vp->sampptr + 3 ) & 3 ] ) >> 11 ) & ~1; + if( vr > 32767 ) + { + vr = 32767; + } + else if( vr < -32768 ) + { + vr = -32768; + } + outx = ( signed short )vr; + +#ifdef DBG_INTRP + fprintf( + stderr, + "V%d: mixfrac=%d: [%d]*%d + [%d]*%d + [%d]*%d + [%d]*%d "\ + "= %d\n", + v, + vl, + G1[ vl ], + vp->sampbuf[ ( vp->sampptr + 3 ) & 3 ], + G2[ vl ], + vp->sampbuf[ ( vp->sampptr + 2 ) & 3 ], + G3[ -vl ], + vp->sampbuf[ ( vp->sampptr + 1 ) & 3 ], + G4[ -vl ], + vp->sampbuf[ vp->sampptr ], + outx + ); +#endif + } + + /* Advance the sample position for next update. */ + vp->mixfrac += vp->pitch; + + outx = ( ( outx * envx ) >> 11 ) & ~1; + DSPregs[ V + 9 ] = outx >> 8; + + vl = ( ( ( int )( signed char )DSPregs[ V ] ) * outx ) >> 7; + vr = ( ( ( int )( signed char )DSPregs[ V + 1 ] ) * outx ) >> 7; + outl += vl; + outr += vr; + if( DSPregs[ 0x4D ] & m ) + { + echol += vl; + echor += vr; + } + } +outl = ( outl * ( signed char )DSPregs[ 0x0C ] ) >> 7; +outr = ( outr * ( signed char )DSPregs[ 0x1C ] ) >> 7; + +#ifndef NO_ECHO +/* Perform echo. First, read mem at current location, and put those samples + into the FIR filter queue. */ +#ifdef DBG_ECHO +fprintf( + stderr, + "Echo delay=%dms, feedback=%d%%\n", + DSPregs[ 0x7D ] * 16, + ( ( signed char )DSPregs[ 0x0D ] * 100 ) / 0x7F + ); +#endif + +echo_base = ( ( DSPregs[ 0x6D ] << 8 ) + echo_ptr ) & 0xFFFF; +FIRlbuf[ FIRptr ] + = ( signed short )LEtoME16( + *( UINT16 * ) + &spc_ram[ echo_base ] + ); +FIRrbuf[ FIRptr ] + = ( signed short )LEtoME16( + *( UINT16 * ) + &spc_ram[ echo_base + sizeof( short ) ] + ); + +/* Now, evaluate the FIR filter, and add the results into the final output. */ +vl = FIRlbuf[ FIRptr ] * ( signed char )DSPregs[ 0x7F ]; +vr = FIRrbuf[ FIRptr ] * ( signed char )DSPregs[ 0x7F ]; +FIRptr = ( FIRptr + 1 ) & 7; +vl += FIRlbuf[ FIRptr ] * ( signed char )DSPregs[ 0x6F ]; +vr += FIRrbuf[ FIRptr ] * ( signed char )DSPregs[ 0x6F ]; +FIRptr = ( FIRptr + 1 ) & 7; +vl += FIRlbuf[ FIRptr ] * ( signed char )DSPregs[ 0x5F ]; +vr += FIRrbuf[ FIRptr ] * ( signed char )DSPregs[ 0x5F ]; +FIRptr = ( FIRptr + 1 ) & 7; +vl += FIRlbuf[ FIRptr ] * ( signed char )DSPregs[ 0x4F ]; +vr += FIRrbuf[ FIRptr ] * ( signed char )DSPregs[ 0x4F ]; +FIRptr = ( FIRptr + 1 ) & 7; +vl += FIRlbuf[ FIRptr ] * ( signed char )DSPregs[ 0x3F ]; +vr += FIRrbuf[ FIRptr ] * ( signed char )DSPregs[ 0x3F ]; +FIRptr = ( FIRptr + 1 ) & 7; +vl += FIRlbuf[ FIRptr ] * ( signed char )DSPregs[ 0x2F ]; +vr += FIRrbuf[ FIRptr ] * ( signed char )DSPregs[ 0x2F ]; +FIRptr = ( FIRptr + 1 ) & 7; +vl += FIRlbuf[ FIRptr ] * ( signed char )DSPregs[ 0x1F ]; +vr += FIRrbuf[ FIRptr ] * ( signed char )DSPregs[ 0x1F ]; +FIRptr = ( FIRptr + 1 ) & 7; +vl += FIRlbuf[ FIRptr ] * ( signed char )DSPregs[ 0x0F ]; +vr += FIRrbuf[ FIRptr ] * ( signed char )DSPregs[ 0x0F ]; + +#ifdef DBG_ECHO +fprintf( + stderr, + "FIR Coefficients: %02X %02X %02X %02X %02X %02X %02X %02X\n", + DSPregs[ 0x0F ], + DSPregs[ 0x1F ], + DSPregs[ 0x2F ], + DSPregs[ 0x3F ], + DSPregs[ 0x4F ], + DSPregs[ 0x5F ], + DSPregs[ 0x6F ], + DSPregs[ 0x7F ] + ); +#endif + +/* FIRptr is left in the position of the oldest sample, the one that will be + replaced next update. */ +outl += vl * ( signed char )DSPregs[ 0x2C ] >> 14; +outr += vr * ( signed char )DSPregs[ 0x3C ] >> 14; + +if( !( DSPregs[ 0x6C ] & 0x20 ) ) + { + /* Add the echo feedback back into the original result, and save that into + memory for use later. */ + echol += vl * ( signed char )DSPregs[ 0x0D ] >> 14; + if( echol > 32767 ) + { + echol = 32767; + } + else if( echol < -32768 ) + { + echol = -32768; + } + echor += vr * ( signed char )DSPregs[ 0x0D ] >> 14; + if( echor > 32767 ) + { + echor = 32767; + } + else if( echor < -32768 ) + { + echor = -32768; + } + +#ifdef DBG_ECHO + fprintf( + stderr, + "Echo: Writing %04X,%04X at location %04X\n", + ( UINT16 )echol, + ( UINT16 )echor, + echo_base + ); +#endif + + *( UINT16 * )&spc_ram[ echo_base ] + = MEtoLE16( ( UINT16 )echol ); + *( UINT16 * )&spc_ram[ echo_base + sizeof( short ) ] + = MEtoLE16( ( UINT16 )echor ); + } + +echo_ptr += 2 * sizeof( short ); +if( echo_ptr >= ( ( DSPregs[ 0x7D ] & 0xF ) << 11 ) ) + { + echo_ptr = 0; + } +#endif /* !defined( NO_ECHO ) */ + +if( sound_ptr ) + { + if( DSPregs[ 0x6C ] & 0x40 ) + { + /* MUTE */ +#ifdef DEBUG + fprintf( stderr, "MUTED!\n" ); +#endif + + *sound_ptr = 0; + sound_ptr++; + *sound_ptr = 0; + sound_ptr++; + } + else + { + if( outl > 32767 ) + { + *sound_ptr = 32767; + } + else if( outl < -32768 ) + { + *sound_ptr = -32768; + } + else + { + *sound_ptr = outl; + } + sound_ptr++; + if( outr > 32767 ) + { + *sound_ptr = 32767; + } + else if( outr < -32768 ) + { + *sound_ptr = -32768; + } + else + { + *sound_ptr = outr; + } + sound_ptr++; + } + } + +} /* DSP_Update() */ + + +/***** AdvanceEnvelope *****/ + +static int AdvanceEnvelope /* Run envelope step & retn ENVX*/ + ( + int v /* Voice to process envelope for*/ + ) +{ +int envx; +int cnt; +int adsr1; +int t; + +envx = voice_state[ v ].envx; + +if( voice_state[ v ].envstate == RELEASE ) + { + /* Docs: "When in the state of "key off". the "click" sound is prevented + by the addition of the fixed value 1/256" WTF??? Alright, I'm going + to choose to interpret that this way: When a note is keyed off, start + the RELEASE state, which subtracts 1/256th each sample period (32kHz). + Note there's no need for a count because it always happens every + update. */ + envx -= 0x8; /* 0x8 / 0x800 = 1/256th */ + if( envx <= 0 ) + { + envx = 0; + keys &= ~( 1 << v ); + return -1; + } + voice_state[ v ].envx = envx; + DSPregs[ ( v << 4 ) + 8 ] = envx >> 8; + +#ifdef DBG_ENV + fprintf( + stderr, + "ENV voice %d: envx=%03X, state=RELEASE\n", + v, + envx + ); +#endif + + return( envx ); + } + +cnt = voice_state[ v ].envcnt; +adsr1 = DSPregs[ ( v << 4 ) + 5 ]; +if( adsr1 & 0x80 ) + { + switch( voice_state[ v ].envstate ) + { + case ATTACK: + /* Docs are very confusing. "AR is multiplied by the fixed value + 1/64..." I believe it means to add 1/64th to ENVX once every + time ATTACK is updated, and that's what I'm going to implement. + */ + t = adsr1 & 0xF; + if( t == 0xF ) + { +#ifdef DBG_ENV + fprintf( stderr, "ENV voice %d: instant attack\n", v ); +#endif + + envx += 0x400; + } + else + { + cnt -= ENVCNT[ ( t << 1 ) + 1 ]; + if( cnt > 0 ) + { + break; + } + envx += 0x20; /* 0x020 / 0x800 = 1/64 */ + cnt = CNT_INIT; + } + + if( envx > 0x7FF ) + { + envx = 0x7FF; + voice_state[ v ].envstate = DECAY; + } + +#ifdef DBG_ENV + fprintf( + stderr, + "ENV voice %d: envx=%03X, state=ATTACK\n", + v, + envx + ); +#endif + + voice_state[ v ].envx = envx; + + break; + + case DECAY: + /* Docs: "DR... [is multiplied] by the fixed value 1-1/256." + Well, at least that makes some sense. Multiplying ENVX by + 255/256 every time DECAY is updated. */ + cnt -= ENVCNT[ ( ( adsr1 >> 3 ) & 0xE ) + 0x10 ]; + if( cnt <= 0 ) + { + cnt = CNT_INIT; + envx -= ( ( envx - 1 ) >> 8 ) + 1; + voice_state[ v ].envx = envx; + } + + if( envx <= 0x100 * ( SL( v ) + 1 ) ) + { + voice_state[ v ].envstate = SUSTAIN; + } + +#ifdef DBG_ENV + fprintf( + stderr, + "ENV voice %d: envx=%03X, state=DECAY\n", + v, + envx + ); +#endif + + break; + + case SUSTAIN: + /* Docs: "SR [is multiplied] by the fixed value 1-1/256." + Multiplying ENVX by 255/256 every time SUSTAIN is updated. */ +#ifdef DBG_ENV + if( ENVCNT[ SR( v ) ] == 0 ) + { + fprintf( + stderr, + "ENV voice %d: envx=%03X, state=SUSTAIN, zero rate\n", + v, + envx + ); + } +#endif + + cnt -= ENVCNT[ SR( v ) ]; + if( cnt > 0 ) + { + break; + } + cnt = CNT_INIT; + envx -= ( ( envx - 1 ) >> 8 ) + 1; + +#ifdef DBG_ENV + fprintf( + stderr, + "ENV voice %d: envx=%03X, state=SUSTAIN\n", + v, + envx + ); +#endif + + voice_state[ v ].envx = envx; + + /* Note: no way out of this state except by explicit KEY OFF (or + switch to GAIN). */ + break; + + case RELEASE: /* Handled earlier to prevent GAIN mode from stopping + KEY OFF events */ + break; + } + } +else + { + /* GAIN mode is set + Note: if the game switches between ADSR and GAIN modes partway + through, should the count be reset, or should it continue from + where it was? Does the DSP actually watch for that bit to + change, or does it just go along with whatever it sees when it + performs the update? I'm going to assume the latter and not + update the count, unless I see a game that obviously wants the + other behavior. The effect would be pretty subtle, in any case. + */ + t = DSPregs[ ( v << 4 ) + 7 ]; + if( t < 0x80 ) + { + envx = t << 4; + voice_state[ v ].envx = envx; + +#ifdef DBG_ENV + fprintf( + stderr, + "ENV voice %d: envx=%03X, state=DIRECT\n", + v, + envx + ); +#endif + } + else + { + switch( t >> 5 ) + { + case 4: + /* Docs: "Decrease (linear): Subtraction of the fixed value + 1/64." */ + cnt -= ENVCNT[ t & 0x1F ]; + if( cnt > 0 ) + { + break; + } + cnt = CNT_INIT; + envx -= 0x020; /* 0x020 / 0x800 = 1/64th */ + if( envx < 0 ) + { + envx = 0; + } + +#ifdef DBG_ENV + fprintf( + stderr, + "ENV voice %d: envx=%03X, state=DECREASE\n", + v, + envx + ); +#endif + + voice_state[ v ].envx = envx; + + break; + + case 5: + /* Docs: "Drecrease <sic> (exponential): Multiplication by + the fixed value 1-1/256." */ + cnt -= ENVCNT[ t & 0x1F ]; + if( cnt > 0 ) + { + break; + } + cnt = CNT_INIT; + envx -= ( ( envx - 1 ) >> 8 ) + 1; + +#ifdef DBG_ENV + fprintf( + stderr, + "ENV voice %d: envx=%03X, state=EXP\n", + v, + envx + ); +#endif + + voice_state[ v ].envx = envx; + + break; + + case 6: + /* Docs: "Increase (linear): Addition of the fixed value + 1/64." */ + cnt -= ENVCNT[ t & 0x1F ]; + if( cnt > 0 ) + { + break; + } + cnt = CNT_INIT; + envx += 0x020; /* 0x020 / 0x800 = 1/64th */ + if( envx > 0x7FF ) + { + envx = 0x7FF; + } + +#ifdef DBG_ENV + fprintf( + stderr, + "ENV voice %d: envx=%03X, state=INCREASE\n", + v, + envx + ); +#endif + + voice_state[ v ].envx = envx; + + break; + + case 7: + /* Docs: "Increase (bent line): Addition of the constant + 1/64 up to .75 of the constaint <sic> 1/256 from .75 to + 1." */ + cnt -= ENVCNT[ t & 0x1F ]; + if( cnt > 0 ) + { + break; + } + cnt = CNT_INIT; + if( envx < 0x600 ) /* 0x600 / 0x800 = .75 */ + { + envx += 0x020; /* 0x020 / 0x800 = 1/64 */ + } + else + { + envx += 0x008; /* 0x008 / 0x800 = 1/256 */ + } + if( envx > 0x7FF ) + { + envx=0x7FF; + } + +#ifdef DBG_ENV + fprintf( + stderr, + "ENV voice %d: envx=%03X, state=INCREASE\n", + v, + envx + ); +#endif + + voice_state[ v ].envx = envx; + + break; + } + } + } + +voice_state[ v ].envcnt = cnt; +DSPregs[ ( v << 4 ) + 8 ] = envx >> 4; + +return( envx ); + +} /* AdvanceEnvelope() */ + +static TIMER_CALLBACK( snes_spc_timer ) +{ + int which = param; + + timers[which].counter++; + if( timers[which].counter >= spc_ram[0xfa + which] ) // minus = + { + timers[which].counter = 0; + spc_ram[0xfd + which]++; + spc_ram[0xfd + which]&= 0xf; + } +} + +void *snes_sh_start(int clock, const struct CustomSound_interface *config) +{ + UINT8 ii; + + /* put IPL image at the top of RAM */ + memcpy(snes_ipl_region, memory_region(REGION_USER5), 64); + + /* default to ROM visible */ + spc_ram[0xf1] = 0x80; + + /* Sort out the ports */ + for( ii = 0; ii < 4; ii++ ) + { + spc_port_in[ii] = 0; + spc_port_out[ii] = 0; + } + + channel = stream_create( 0, 2, 32000, NULL, snes_sh_update ); + + /* Initialize the timers */ + timers[0].timer = timer_alloc( snes_spc_timer ); + timer_adjust( timers[0].timer, ATTOTIME_IN_HZ(8000), 0, ATTOTIME_IN_HZ(8000) ); + timer_enable( timers[0].timer, 0 ); + timers[1].timer = timer_alloc( snes_spc_timer ); + timer_adjust( timers[1].timer, ATTOTIME_IN_HZ(8000), 1, ATTOTIME_IN_HZ(8000) ); + timer_enable( timers[1].timer, 0 ); + timers[2].timer = timer_alloc( snes_spc_timer ); + timer_adjust( timers[2].timer, ATTOTIME_IN_HZ(64000), 2, ATTOTIME_IN_HZ(64000) ); + timer_enable( timers[2].timer, 0 ); + + DSP_Reset(); + + return auto_malloc(1); +} + +void snes_sh_update( void *param, stream_sample_t **inputs, stream_sample_t **outputs, int length ) +{ + int i; + short mix[2]; + + for (i = 0; i < length; i++) + { + mix[0] = mix[1] = 0; + DSP_Update(mix); + + /* Update the buffers */ + outputs[0][i] = (stream_sample_t)mix[0]; + outputs[1][i] = (stream_sample_t)mix[1]; + } +} + +/*************************** + * I/O for DSP * + ***************************/ + +static READ8_HANDLER( snes_dsp_io_r ) +{ + stream_update(channel); + +#ifdef NO_ENVX + if( 8 == ( SPCRAM[ 0xF2 ] & 0xF ) ) + { + DSPregs[ SPCRAM[ 0xF2 ] ] = 0; + } +#endif + + return DSPregs[offset & 0x7f]; +} + +static WRITE8_HANDLER( snes_dsp_io_w ) +{ + stream_update(channel); + + if( 0x7C == offset ) + { + DSP_WRITE_7C(data); + } + else + { + DSPregs[ offset ] = data; + } +} + +/*************************** + * I/O for SPC700 * + ***************************/ +READ8_HANDLER( spc_io_r ) +{ + switch( offset ) /* Offset is from 0x00f0 */ + { + case 0x2: /* Register address */ + return spc_ram[0xf2]; + case 0x3: /* Register data */ + return snes_dsp_io_r( spc_ram[0xf2] ); + case 0x4: /* Port 0 */ + case 0x5: /* Port 1 */ + case 0x6: /* Port 2 */ + case 0x7: /* Port 3 */ +// mame_printf_debug("SPC: rd %02x @ %d, PC=%x\n", spc_port_in[offset-4], offset-4, activecpu_get_pc()); + return spc_port_in[offset - 4]; + case 0xA: /* Timer 0 */ + case 0xB: /* Timer 1 */ + case 0xC: /* Timer 2 */ + break; + case 0xD: /* Counter 0 */ + case 0xE: /* Counter 1 */ + case 0xF: /* Counter 2 */ + { + UINT8 value = spc_ram[0xf0 + offset] & 0xf; + spc_ram[0xf0 + offset] = 0; + return value; + } + } + return 0xff; +} + +WRITE8_HANDLER( spc_io_w ) +{ + switch( offset ) /* Offset is from 0x00f0 */ + { + case 0x1: /* Control */ + if( data & 0x1 && !timers[0].enabled ) + { + timers[0].counter = 0; + spc_ram[0xfd] = 0; + } + if( data & 0x2 && !timers[1].enabled ) + { + timers[1].counter = 0; + spc_ram[0xfe] = 0; + } + if( data & 0x4 && !timers[2].enabled ) + { + timers[2].counter = 0; + spc_ram[0xff] = 0; + } + timers[0].enabled = data & 0x1; + timer_enable( timers[0].timer, timers[0].enabled ); + timers[1].enabled = (data & 0x2) >> 1; + timer_enable( timers[1].timer, timers[1].enabled ); + timers[2].enabled = (data & 0x4) >> 2; + timer_enable( timers[2].timer, timers[2].enabled ); + if( data & 0x10 ) + { + spc_port_in[0] = 0; + spc_port_in[1] = 0; + } + if( data & 0x20 ) + { + spc_port_in[2] = 0; + spc_port_in[3] = 0; + } + + if ((data & 0x80) != (spc_ram[0xf1] & 0x80)) + { + if (data & 0x80) + { + memcpy(snes_ipl_region, memory_region(REGION_USER5), 64); + } + else + { + memcpy(snes_ipl_region, &spc_ram[0xffc0], 64); + } + } + break; + case 0x2: /* Register address */ + break; + case 0x3: /* Register data */ + snes_dsp_io_w( spc_ram[0xf2], data ); + break; + case 0x4: /* Port 0 */ + case 0x5: /* Port 1 */ + case 0x6: /* Port 2 */ + case 0x7: /* Port 3 */ +// mame_printf_debug("SPC: %02x to APU @ %d (PC=%x)\n", data, offset&3, activecpu_get_pc()); + spc_port_out[offset - 4] = data; + cpu_boost_interleave(attotime_zero, ATTOTIME_IN_USEC(20)); + break; + case 0xA: /* Timer 0 */ + case 0xB: /* Timer 1 */ + case 0xC: /* Timer 2 */ + if (data == 0) data = 255; + break; + case 0xD: /* Counter 0 */ + case 0xE: /* Counter 1 */ + case 0xF: /* Counter 2 */ + return; + } + + spc_ram[0xf0 + offset] = data; +} + +READ8_HANDLER( spc_ram_r ) +{ + return spc_ram[offset]; +} + +WRITE8_HANDLER( spc_ram_w ) +{ + spc_ram[offset] = data; + + // if RAM is mapped in, mirror accordingly + if ((!(spc_ram[0xf1] & 0x80)) && (offset >= 0xffc0)) + { + snes_ipl_region[offset-0xffc0] = data; + } +} + +READ8_HANDLER( spc_ipl_r ) +{ + return snes_ipl_region[offset]; +} + |