diff options
| author | 2019-09-21 12:41:14 +0200 | |
|---|---|---|
| committer | 2019-09-21 12:41:14 +0200 | |
| commit | 3517c6fcb4a919e25965e17e4355f912ad052e36 (patch) | |
| tree | 35930971fe05de7a3ba715bb11650eeedf6d5469 /src | |
| parent | bb68b228c57eab1a60b1cb03a5cf835a26fd8e5b (diff) | |
acorn_vidc.cpp: generate u255 law sound table on device start [Olivier Galibert, Angelo Salese]
Diffstat (limited to 'src')
| -rw-r--r-- | src/devices/machine/acorn_vidc.cpp | 58 | ||||
| -rw-r--r-- | src/devices/machine/acorn_vidc.h | 1 | ||||
| -rw-r--r-- | src/mame/drivers/riscpc.cpp | 4 | ||||
| -rw-r--r-- | src/mame/machine/archimds.cpp | 9 |
4 files changed, 27 insertions, 45 deletions
diff --git a/src/devices/machine/acorn_vidc.cpp b/src/devices/machine/acorn_vidc.cpp index 0b582f25ae7..97056c0b5a9 100644 --- a/src/devices/machine/acorn_vidc.cpp +++ b/src/devices/machine/acorn_vidc.cpp @@ -158,6 +158,23 @@ void acorn_vidc10_device::device_start() m_video_timer = timer_alloc(TIMER_VIDEO); m_sound_timer = timer_alloc(TIMER_SOUND); + + // generate u255 law lookup table + // cfr. page 48 of the VIDC20 manual, page 33 of the VIDC manual + // TODO: manual mentions a format difference between VIDC10 revisions + for (int rawval = 0; rawval < 256; rawval++) + { + uint8_t chord = rawval >> 5; + uint8_t point = (rawval & 0x1e) >> 1; + bool sign = rawval & 1; + int16_t result = ((16+point)<<chord)-16; + + if (sign) + result = -result; + + m_ulaw_lookup[rawval] = result*8; + } + save_pointer(NAME(m_ulaw_lookup), 256); } @@ -385,47 +402,8 @@ WRITE32_MEMBER( acorn_vidc10_device::sound_frequency_w ) void acorn_vidc10_device::write_dac(uint8_t channel, uint8_t data) { - uint8_t ulaw_comp; int16_t res; - static constexpr int16_t mulawTable[256] = - { - -32124,-31100,-30076,-29052,-28028,-27004,-25980,-24956, - -23932,-22908,-21884,-20860,-19836,-18812,-17788,-16764, - -15996,-15484,-14972,-14460,-13948,-13436,-12924,-12412, - -11900,-11388,-10876,-10364, -9852, -9340, -8828, -8316, - -7932, -7676, -7420, -7164, -6908, -6652, -6396, -6140, - -5884, -5628, -5372, -5116, -4860, -4604, -4348, -4092, - -3900, -3772, -3644, -3516, -3388, -3260, -3132, -3004, - -2876, -2748, -2620, -2492, -2364, -2236, -2108, -1980, - -1884, -1820, -1756, -1692, -1628, -1564, -1500, -1436, - -1372, -1308, -1244, -1180, -1116, -1052, -988, -924, - -876, -844, -812, -780, -748, -716, -684, -652, - -620, -588, -556, -524, -492, -460, -428, -396, - -372, -356, -340, -324, -308, -292, -276, -260, - -244, -228, -212, -196, -180, -164, -148, -132, - -120, -112, -104, -96, -88, -80, -72, -64, - -56, -48, -40, -32, -24, -16, -8, -1, - 32124, 31100, 30076, 29052, 28028, 27004, 25980, 24956, - 23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764, - 15996, 15484, 14972, 14460, 13948, 13436, 12924, 12412, - 11900, 11388, 10876, 10364, 9852, 9340, 8828, 8316, - 7932, 7676, 7420, 7164, 6908, 6652, 6396, 6140, - 5884, 5628, 5372, 5116, 4860, 4604, 4348, 4092, - 3900, 3772, 3644, 3516, 3388, 3260, 3132, 3004, - 2876, 2748, 2620, 2492, 2364, 2236, 2108, 1980, - 1884, 1820, 1756, 1692, 1628, 1564, 1500, 1436, - 1372, 1308, 1244, 1180, 1116, 1052, 988, 924, - 876, 844, 812, 780, 748, 716, 684, 652, - 620, 588, 556, 524, 492, 460, 428, 396, - 372, 356, 340, 324, 308, 292, 276, 260, - 244, 228, 212, 196, 180, 164, 148, 132, - 120, 112, 104, 96, 88, 80, 72, 64, - 56, 48, 40, 32, 24, 16, 8, 0 - }; - - uint8_t ulaw_temp = data ^ 0xff; - ulaw_comp = (ulaw_temp>>1) | ((ulaw_temp&1)<<7); - res = mulawTable[ulaw_comp]; + res = m_ulaw_lookup[data]; m_dac[channel & 7]->write(res); } diff --git a/src/devices/machine/acorn_vidc.h b/src/devices/machine/acorn_vidc.h index 08bf93dd571..ff6cf0ecf11 100644 --- a/src/devices/machine/acorn_vidc.h +++ b/src/devices/machine/acorn_vidc.h @@ -116,6 +116,7 @@ private: u8 m_stereo_image[8]; const float m_sound_input_gain = 0.05; const int m_sound_max_channels = 8; + int16_t m_ulaw_lookup[256]; void refresh_sound_frequency(); inline void refresh_stereo_image(uint8_t channel); }; diff --git a/src/mame/drivers/riscpc.cpp b/src/mame/drivers/riscpc.cpp index a1b1d7e0c99..cc7e8f8a57c 100644 --- a/src/mame/drivers/riscpc.cpp +++ b/src/mame/drivers/riscpc.cpp @@ -1009,7 +1009,7 @@ void riscpc_state::a7000p(machine_config &config) void riscpc_state::sarpc(machine_config &config) { /* Basic machine hardware */ - ARM7(config, m_maincpu, 202000000); // StrongARM + SA1110(config, m_maincpu, 202000000); // StrongARM m_maincpu->set_addrmap(AS_PROGRAM, &riscpc_state::riscpc_map); base_config(config); } @@ -1017,7 +1017,7 @@ void riscpc_state::sarpc(machine_config &config) void riscpc_state::sarpc_j233(machine_config &config) { /* Basic machine hardware */ - ARM7(config, m_maincpu, 233000000); // StrongARM + SA1110(config, m_maincpu, 233000000); // StrongARM m_maincpu->set_addrmap(AS_PROGRAM, &riscpc_state::riscpc_map); base_config(config); } diff --git a/src/mame/machine/archimds.cpp b/src/mame/machine/archimds.cpp index 6637f13d44c..c7624291993 100644 --- a/src/mame/machine/archimds.cpp +++ b/src/mame/machine/archimds.cpp @@ -882,19 +882,22 @@ WRITE32_MEMBER(archimedes_state::archimedes_memc_w) break; case 4: /* sound start */ - //logerror("MEMC: SNDSTART %08x\n",data); archimedes_clear_irq_b(ARCHIMEDES_IRQB_SOUND_EMPTY); m_vidc_sndstart = 0x2000000 | ((data>>2)&0x7fff)*16; + //printf("MEMC: SNDSTART %08x\n",m_vidc_sndstart); break; case 5: /* sound end */ - //logerror("MEMC: SNDEND %08x\n",data); // end buffer is actually +16 bytes wrt sound start + // TODO: it actually don't apply for ertictac and poizone? m_vidc_sndend = 0x2000000 | (((data>>2)+1)&0x7fff)*16; + //printf("MEMC: SNDEND %08x\n",m_vidc_sndend); break; case 6: - m_vidc_sndcur = 0; + //printf("MEMC: SNDPTR\n"); + m_vidc_sndcur = m_vidc_sndstart; + m_vidc_sndendcur = m_vidc_sndend; archimedes_request_irq_b(ARCHIMEDES_IRQB_SOUND_EMPTY); break; |
