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Diffstat (limited to 'src/mame/audio/segasnd.cpp')
-rw-r--r-- | src/mame/audio/segasnd.cpp | 906 |
1 files changed, 906 insertions, 0 deletions
diff --git a/src/mame/audio/segasnd.cpp b/src/mame/audio/segasnd.cpp new file mode 100644 index 00000000000..97fdf3a1f41 --- /dev/null +++ b/src/mame/audio/segasnd.cpp @@ -0,0 +1,906 @@ +// license:BSD-3-Clause +// copyright-holders:Aaron Giles +/*************************************************************************** + + segasnd.c + + Sound boards for early Sega G-80 based games. + +***************************************************************************/ + +#include "emu.h" +#include "sound/sp0250.h" +#include "segasnd.h" + + +#define VERBOSE 0 +#define LOG(x) do { if (VERBOSE) logerror x; } while (0) + + +/*************************************************************************** + CONSTANTS +***************************************************************************/ + +#define SPEECH_MASTER_CLOCK 3120000 + +#define USB_MASTER_CLOCK 6000000 +#define USB_2MHZ_CLOCK (USB_MASTER_CLOCK/3) +#define USB_PCS_CLOCK (USB_2MHZ_CLOCK/2) +#define USB_GOS_CLOCK (USB_2MHZ_CLOCK/16/4) +#define MM5837_CLOCK 100000 + +#define SAMPLE_RATE (USB_2MHZ_CLOCK/8) + + + +/*************************************************************************** + INLINE FUNCTIONS +***************************************************************************/ + +INLINE void configure_filter(g80_filter_state *state, double r, double c) +{ + state->capval = 0; + state->exponent = 1.0 - exp(-1.0 / (r * c * SAMPLE_RATE)); +} + + +INLINE double step_rc_filter(g80_filter_state *state, double input) +{ + state->capval += (input - state->capval) * state->exponent; + return state->capval; +} + + +INLINE double step_cr_filter(g80_filter_state *state, double input) +{ + double result = (input - state->capval); + state->capval += (input - state->capval) * state->exponent; + return result; +} + + + +/*************************************************************************** + SPEECH BOARD +***************************************************************************/ + +const device_type SEGASPEECH = &device_creator<speech_sound_device>; + +speech_sound_device::speech_sound_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : device_t(mconfig, SEGASPEECH, "Sega Speech Sound Board", tag, owner, clock, "sega_speech_sound", __FILE__), + device_sound_interface(mconfig, *this), + m_drq(0), + m_latch(0), + m_t0(0), + m_p2(0), + m_speech(NULL) +{ +} + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void speech_sound_device::device_start() +{ + m_speech = machine().root_device().memregion("speech")->base(); + + save_item(NAME(m_latch)); + save_item(NAME(m_t0)); + save_item(NAME(m_p2)); + save_item(NAME(m_drq)); +} + + +/************************************* + * + * i8035 port accessors + * + *************************************/ + + + +READ8_MEMBER( speech_sound_device::t0_r ) +{ + return m_t0; +} + +READ8_MEMBER( speech_sound_device::t1_r ) +{ + return m_drq; +} + +READ8_MEMBER( speech_sound_device::p1_r ) +{ + return m_latch & 0x7f; +} + +READ8_MEMBER( speech_sound_device::rom_r ) +{ + return m_speech[0x100 * (m_p2 & 0x3f) + offset]; +} + +WRITE8_MEMBER( speech_sound_device::p1_w ) +{ + if (!(data & 0x80)) + m_t0 = 0; +} + +WRITE8_MEMBER( speech_sound_device::p2_w ) +{ + m_p2 = data; +} + + + +/************************************* + * + * i8035 port accessors + * + *************************************/ + +WRITE_LINE_MEMBER(speech_sound_device::drq_w) +{ + m_drq = (state == ASSERT_LINE); +} + + + +/************************************* + * + * External access + * + *************************************/ + +TIMER_CALLBACK_MEMBER( speech_sound_device::delayed_speech_w ) +{ + int data = param; + UINT8 old = m_latch; + + /* all 8 bits are latched */ + m_latch = data; + + /* the high bit goes directly to the INT line */ + machine().device("audiocpu")->execute().set_input_line(0, (data & 0x80) ? CLEAR_LINE : ASSERT_LINE); + + /* a clock on the high bit clocks a 1 into T0 */ + if (!(old & 0x80) && (data & 0x80)) + m_t0 = 1; +} + + +WRITE8_MEMBER( speech_sound_device::data_w ) +{ + space.machine().scheduler().synchronize(timer_expired_delegate(FUNC(speech_sound_device::delayed_speech_w), this), data); +} + + +WRITE8_MEMBER( speech_sound_device::control_w ) +{ + LOG(("Speech control = %X\n", data)); +} + + +//------------------------------------------------- +// sound_stream_update - handle a stream update +//------------------------------------------------- + +void speech_sound_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples) +{ +} + + +/************************************* + * + * Speech board address maps + * + *************************************/ + +static ADDRESS_MAP_START( speech_map, AS_PROGRAM, 8, driver_device ) + AM_RANGE(0x0000, 0x07ff) AM_MIRROR(0x0800) AM_ROM +ADDRESS_MAP_END + + +static ADDRESS_MAP_START( speech_portmap, AS_IO, 8, driver_device ) + AM_RANGE(0x00, 0xff) AM_DEVREAD("segaspeech", speech_sound_device, rom_r) + AM_RANGE(0x00, 0xff) AM_DEVWRITE("speech", sp0250_device, write) + AM_RANGE(MCS48_PORT_P1, MCS48_PORT_P1) AM_DEVREADWRITE("segaspeech", speech_sound_device, p1_r, p1_w) + AM_RANGE(MCS48_PORT_P2, MCS48_PORT_P2) AM_DEVWRITE("segaspeech", speech_sound_device, p2_w) + AM_RANGE(MCS48_PORT_T0, MCS48_PORT_T0) AM_DEVREAD("segaspeech", speech_sound_device, t0_r) + AM_RANGE(MCS48_PORT_T1, MCS48_PORT_T1) AM_DEVREAD("segaspeech", speech_sound_device, t1_r) +ADDRESS_MAP_END + + +/************************************* + * + * Speech board machine drivers + * + *************************************/ + +MACHINE_CONFIG_FRAGMENT( sega_speech_board ) + + /* CPU for the speech board */ + MCFG_CPU_ADD("audiocpu", I8035, SPEECH_MASTER_CLOCK) /* divide by 15 in CPU */ + MCFG_CPU_PROGRAM_MAP(speech_map) + MCFG_CPU_IO_MAP(speech_portmap) + + /* sound hardware */ + MCFG_SOUND_ADD("segaspeech", SEGASPEECH, 0) + MCFG_SOUND_ADD("speech", SP0250, SPEECH_MASTER_CLOCK) + MCFG_SP0250_DRQ_CALLBACK(DEVWRITELINE("segaspeech", speech_sound_device, drq_w)) + MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 1.0) +MACHINE_CONFIG_END + + + +/*************************************************************************** + UNIVERSAL SOUND BOARD +***************************************************************************/ + +const device_type SEGAUSB = &device_creator<usb_sound_device>; + +usb_sound_device::usb_sound_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source) + : device_t(mconfig, type, name, tag, owner, clock, shortname, source), + device_sound_interface(mconfig, *this), + m_ourcpu(*this, "ourcpu"), + m_stream(NULL), + m_in_latch(0), + m_out_latch(0), + m_last_p2_value(0), + m_program_ram(*this, "pgmram"), + m_work_ram(*this, "workram"), + m_work_ram_bank(0), + m_t1_clock(0), + m_t1_clock_mask(0), + m_noise_shift(0), + m_noise_state(0), + m_noise_subcount(0) +{ +} + +usb_sound_device::usb_sound_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : device_t(mconfig, SEGAUSB, "Sega Universal Sound Board", tag, owner, clock, "segausb", __FILE__), + device_sound_interface(mconfig, *this), + m_ourcpu(*this, "ourcpu"), + m_program_ram(*this, "pgmram"), + m_work_ram(*this, "workram") +{ +} + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void usb_sound_device::device_start() +{ + g80_filter_state temp; + int tchan, tgroup; + + /* find the CPU we are associated with */ + m_maincpu = machine().device("maincpu"); + assert(m_maincpu != NULL); + + /* create a sound stream */ + m_stream = machine().sound().stream_alloc(*this, 0, 1, SAMPLE_RATE); + + /* initialize state */ + m_noise_shift = 0x15555; + + for (tgroup = 0; tgroup < 3; tgroup++) + { + timer8253 *g = &m_timer_group[tgroup]; + configure_filter(&g->chan_filter[0], 10e3, 1e-6); + configure_filter(&g->chan_filter[1], 10e3, 1e-6); + configure_filter(&g->gate1, 100e3, 0.01e-6); + configure_filter(&g->gate2, 2 * 100e3, 0.01e-6); + } + + configure_filter(&temp, 100e3, 0.01e-6); + m_gate_rc1_exp[0] = temp.exponent; + configure_filter(&temp, 1e3, 0.01e-6); + m_gate_rc1_exp[1] = temp.exponent; + configure_filter(&temp, 2 * 100e3, 0.01e-6); + m_gate_rc2_exp[0] = temp.exponent; + configure_filter(&temp, 2 * 1e3, 0.01e-6); + m_gate_rc2_exp[1] = temp.exponent; + + configure_filter(&m_noise_filters[0], 2.7e3 + 2.7e3, 1.0e-6); + configure_filter(&m_noise_filters[1], 2.7e3 + 1e3, 0.30e-6); + configure_filter(&m_noise_filters[2], 2.7e3 + 270, 0.15e-6); + configure_filter(&m_noise_filters[3], 2.7e3 + 0, 0.082e-6); + configure_filter(&m_noise_filters[4], 33e3, 0.1e-6); + + configure_filter(&m_final_filter, 100e3, 4.7e-6); + + /* register for save states */ + save_item(NAME(m_in_latch)); + save_item(NAME(m_out_latch)); + save_item(NAME(m_last_p2_value)); + save_item(NAME(m_work_ram_bank)); + save_item(NAME(m_t1_clock)); + + for (tgroup = 0; tgroup < 3; tgroup++) + { + timer8253 *group = &m_timer_group[tgroup]; + for (tchan = 0; tchan < 3; tchan++) + { + timer8253_channel *channel = &group->chan[tchan]; + save_item(NAME(channel->holding), tgroup * 3 + tchan); + save_item(NAME(channel->latchmode), tgroup * 3 + tchan); + save_item(NAME(channel->latchtoggle), tgroup * 3 + tchan); + save_item(NAME(channel->clockmode), tgroup * 3 + tchan); + save_item(NAME(channel->bcdmode), tgroup * 3 + tchan); + save_item(NAME(channel->output), tgroup * 3 + tchan); + save_item(NAME(channel->lastgate), tgroup * 3 + tchan); + save_item(NAME(channel->gate), tgroup * 3 + tchan); + save_item(NAME(channel->subcount), tgroup * 3 + tchan); + save_item(NAME(channel->count), tgroup * 3 + tchan); + save_item(NAME(channel->remain), tgroup * 3 + tchan); + } + save_item(NAME(group->env), tgroup); + save_item(NAME(group->chan_filter[0].capval), tgroup); + save_item(NAME(group->chan_filter[1].capval), tgroup); + save_item(NAME(group->gate1.capval), tgroup); + save_item(NAME(group->gate2.capval), tgroup); + save_item(NAME(group->config), tgroup); + } + + save_item(NAME(m_timer_mode)); + save_item(NAME(m_noise_shift)); + save_item(NAME(m_noise_state)); + save_item(NAME(m_noise_subcount)); + save_item(NAME(m_final_filter.capval)); + save_item(NAME(m_noise_filters[0].capval)); + save_item(NAME(m_noise_filters[1].capval)); + save_item(NAME(m_noise_filters[2].capval)); + save_item(NAME(m_noise_filters[3].capval)); + save_item(NAME(m_noise_filters[4].capval)); +} + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void usb_sound_device::device_reset() +{ + /* halt the USB CPU at reset time */ + m_ourcpu->set_input_line(INPUT_LINE_RESET, ASSERT_LINE); + + /* start the clock timer */ + m_t1_clock_mask = 0x10; +} + +/************************************* + * + * Initialization/reset + * + *************************************/ + +TIMER_DEVICE_CALLBACK_MEMBER( usb_sound_device::increment_t1_clock_timer_cb ) +{ + /* only increment if it is not being forced clear */ + if (!(m_last_p2_value & 0x80)) + m_t1_clock++; +} + +/************************************* + * + * External access + * + *************************************/ + +READ8_MEMBER( usb_sound_device::status_r ) +{ + LOG(("%04X:usb_data_r = %02X\n", m_maincpu->safe_pc(), (m_out_latch & 0x81) | (m_in_latch & 0x7e))); + + m_maincpu->execute().adjust_icount(-200); + + /* only bits 0 and 7 are controlled by the I8035; the remaining */ + /* bits 1-6 reflect the current input latch values */ + return (m_out_latch & 0x81) | (m_in_latch & 0x7e); +} + + +TIMER_CALLBACK_MEMBER( usb_sound_device::delayed_usb_data_w ) +{ + int data = param; + + /* look for rising/falling edges of bit 7 to control the RESET line */ + m_ourcpu->set_input_line(INPUT_LINE_RESET, (data & 0x80) ? ASSERT_LINE : CLEAR_LINE); + + /* if the CLEAR line is set, the low 7 bits of the input are ignored */ + if ((m_last_p2_value & 0x40) == 0) + data &= ~0x7f; + + /* update the effective input latch */ + m_in_latch = data; +} + + +WRITE8_MEMBER( usb_sound_device::data_w ) +{ + LOG(("%04X:usb_data_w = %02X\n", m_maincpu->safe_pc(), data)); + space.machine().scheduler().synchronize(timer_expired_delegate(FUNC(usb_sound_device::delayed_usb_data_w), this), data); + + /* boost the interleave so that sequences can be sent */ + space.machine().scheduler().boost_interleave(attotime::zero, attotime::from_usec(250)); +} + + +READ8_MEMBER( usb_sound_device::ram_r ) +{ + return m_program_ram[offset]; +} + + +WRITE8_MEMBER( usb_sound_device::ram_w ) +{ + if (m_in_latch & 0x80) + m_program_ram[offset] = data; + else + LOG(("%04X:sega_usb_ram_w(%03X) = %02X while /LOAD disabled\n", m_maincpu->safe_pc(), offset, data)); +} + + + +/************************************* + * + * I8035 port accesses + * + *************************************/ + +READ8_MEMBER( usb_sound_device::p1_r ) +{ + /* bits 0-6 are inputs and map to bits 0-6 of the input latch */ + if ((m_in_latch & 0x7f) != 0) + LOG(("%03X: P1 read = %02X\n", m_maincpu->safe_pc(), m_in_latch & 0x7f)); + return m_in_latch & 0x7f; +} + + +WRITE8_MEMBER( usb_sound_device::p1_w ) +{ + /* bit 7 maps to bit 0 on the output latch */ + m_out_latch = (m_out_latch & 0xfe) | (data >> 7); + LOG(("%03X: P1 write = %02X\n", m_maincpu->safe_pc(), data)); +} + + +WRITE8_MEMBER( usb_sound_device::p2_w ) +{ + UINT8 old = m_last_p2_value; + m_last_p2_value = data; + + /* low 2 bits control the bank of work RAM we are addressing */ + m_work_ram_bank = data & 3; + + /* bit 6 controls the "ready" bit output to the host */ + /* it also clears the input latch from the host (active low) */ + m_out_latch = ((data & 0x40) << 1) | (m_out_latch & 0x7f); + if ((data & 0x40) == 0) + m_in_latch = 0; + + /* bit 7 controls the reset on the upper counter at U33 */ + if ((old & 0x80) && !(data & 0x80)) + m_t1_clock = 0; + + LOG(("%03X: P2 write -> bank=%d ready=%d clock=%d\n", m_maincpu->safe_pc(), data & 3, (data >> 6) & 1, (data >> 7) & 1)); +} + + +READ8_MEMBER( usb_sound_device::t1_r ) +{ + /* T1 returns 1 based on the value of the T1 clock; the exact */ + /* pattern is determined by one or more jumpers on the board. */ + return (m_t1_clock & m_t1_clock_mask) != 0; +} + + + +/************************************* + * + * Sound generation + * + *************************************/ + +INLINE void clock_channel(timer8253_channel *ch) +{ + UINT8 lastgate = ch->lastgate; + + /* update the gate */ + ch->lastgate = ch->gate; + + /* if we're holding, skip */ + if (ch->holding) + return; + + /* switch off the clock mode */ + switch (ch->clockmode) + { + /* oneshot; waits for trigger to restart */ + case 1: + if (!lastgate && ch->gate) + { + ch->output = 0; + ch->remain = ch->count; + } + else + { + if (--ch->remain == 0) + ch->output = 1; + } + break; + + /* square wave: counts down by 2 and toggles output */ + case 3: + ch->remain = (ch->remain - 1) & ~1; + if (ch->remain == 0) + { + ch->output ^= 1; + ch->remain = ch->count; + } + break; + } +} + + +/************************************* + * + * USB timer and envelope controls + * + *************************************/ + +void usb_sound_device::timer_w(int which, UINT8 offset, UINT8 data) +{ + timer8253 *g = &m_timer_group[which]; + timer8253_channel *ch; + int was_holding; + + m_stream->update(); + + /* switch off the offset */ + switch (offset) + { + case 0: + case 1: + case 2: + ch = &g->chan[offset]; + was_holding = ch->holding; + + /* based on the latching mode */ + switch (ch->latchmode) + { + case 1: /* low word only */ + ch->count = data; + ch->holding = FALSE; + break; + + case 2: /* high word only */ + ch->count = data << 8; + ch->holding = FALSE; + break; + + case 3: /* low word followed by high word */ + if (ch->latchtoggle == 0) + { + ch->count = (ch->count & 0xff00) | (data & 0x00ff); + ch->latchtoggle = 1; + } + else + { + ch->count = (ch->count & 0x00ff) | (data << 8); + ch->holding = FALSE; + ch->latchtoggle = 0; + } + break; + } + + /* if we're not holding, load the initial count for some modes */ + if (was_holding && !ch->holding) + ch->remain = 1; + break; + + case 3: + /* break out the components */ + if (((data & 0xc0) >> 6) < 3) + { + ch = &g->chan[(data & 0xc0) >> 6]; + + /* extract the bits */ + ch->holding = TRUE; + ch->latchmode = (data >> 4) & 3; + ch->clockmode = (data >> 1) & 7; + ch->bcdmode = (data >> 0) & 1; + ch->latchtoggle = 0; + ch->output = (ch->clockmode == 1); + } + break; + } +} + + +void usb_sound_device::env_w(int which, UINT8 offset, UINT8 data) +{ + timer8253 *g = &m_timer_group[which]; + + m_stream->update(); + + if (offset < 3) + g->env[offset] = (double)data; + else + g->config = data & 1; +} + + + +/************************************* + * + * USB work RAM access + * + *************************************/ + +READ8_MEMBER( usb_sound_device::workram_r ) +{ + offset += 256 * m_work_ram_bank; + return m_work_ram[offset]; +} + + +WRITE8_MEMBER( usb_sound_device::workram_w ) +{ + offset += 256 * m_work_ram_bank; + m_work_ram[offset] = data; + + /* writes to the low 32 bytes go to various controls */ + switch (offset & ~3) + { + case 0x00: /* CTC0 */ + timer_w(0, offset & 3, data); + break; + + case 0x04: /* ENV0 */ + env_w(0, offset & 3, data); + break; + + case 0x08: /* CTC1 */ + timer_w(1, offset & 3, data); + break; + + case 0x0c: /* ENV1 */ + env_w(1, offset & 3, data); + break; + + case 0x10: /* CTC2 */ + timer_w(2, offset & 3, data); + break; + + case 0x14: /* ENV2 */ + env_w(2, offset & 3, data); + break; + } +} + +//------------------------------------------------- +// sound_stream_update - handle a stream update +//------------------------------------------------- + +void usb_sound_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples) +{ + stream_sample_t *dest = outputs[0]; + + /* iterate over samples */ + while (samples--) + { + double noiseval; + double sample = 0; + int group; + int step; + + + /*---------------- + Noise Source + ---------------- + + RC + MM5837 ---> FILTER ---> CR FILTER ---> 3.2x AMP ---> NOISE + LADDER + */ + + /* update the noise source */ + for (step = USB_2MHZ_CLOCK / SAMPLE_RATE; step >= m_noise_subcount; step -= m_noise_subcount) + { + m_noise_shift = (m_noise_shift << 1) | (((m_noise_shift >> 13) ^ (m_noise_shift >> 16)) & 1); + m_noise_state = (m_noise_shift >> 16) & 1; + m_noise_subcount = USB_2MHZ_CLOCK / MM5837_CLOCK; + } + m_noise_subcount -= step; + + /* update the filtered noise value -- this is just an approximation to the pink noise filter */ + /* being applied on the PCB, but it sounds pretty close */ + m_noise_filters[0].capval = 0.99765 * m_noise_filters[0].capval + m_noise_state * 0.0990460; + m_noise_filters[1].capval = 0.96300 * m_noise_filters[1].capval + m_noise_state * 0.2965164; + m_noise_filters[2].capval = 0.57000 * m_noise_filters[2].capval + m_noise_state * 1.0526913; + noiseval = m_noise_filters[0].capval + m_noise_filters[1].capval + m_noise_filters[2].capval + m_noise_state * 0.1848; + + /* final output goes through a CR filter; the scaling factor is arbitrary to get the noise to the */ + /* correct relative volume */ + noiseval = step_cr_filter(&m_noise_filters[4], noiseval); + noiseval *= 0.075; + + /* there are 3 identical groups of circuits, each with its own 8253 */ + for (group = 0; group < 3; group++) + { + timer8253 *g = &m_timer_group[group]; + double chan0, chan1, chan2, mix; + + + /*------------- + Channel 0 + ------------- + + 8253 CR AD7524 + OUT0 ---> FILTER ---> BUFFER---> VRef ---> 100k ---> mix + */ + + /* channel 0 clocks with the PCS clock */ + for (step = USB_2MHZ_CLOCK / SAMPLE_RATE; step >= g->chan[0].subcount; step -= g->chan[0].subcount) + { + g->chan[0].subcount = USB_2MHZ_CLOCK / USB_PCS_CLOCK; + g->chan[0].gate = 1; + clock_channel(&g->chan[0]); + } + g->chan[0].subcount -= step; + + /* channel 0 is mixed in with a resistance of 100k */ + chan0 = step_cr_filter(&g->chan_filter[0], g->chan[0].output) * g->env[0] * (1.0/100.0); + + + /*------------- + Channel 1 + ------------- + + 8253 CR AD7524 + OUT1 ---> FILTER ---> BUFFER---> VRef ---> 100k ---> mix + */ + + /* channel 1 clocks with the PCS clock */ + for (step = USB_2MHZ_CLOCK / SAMPLE_RATE; step >= g->chan[1].subcount; step -= g->chan[1].subcount) + { + g->chan[1].subcount = USB_2MHZ_CLOCK / USB_PCS_CLOCK; + g->chan[1].gate = 1; + clock_channel(&g->chan[1]); + } + g->chan[1].subcount -= step; + + /* channel 1 is mixed in with a resistance of 100k */ + chan1 = step_cr_filter(&g->chan_filter[1], g->chan[1].output) * g->env[1] * (1.0/100.0); + + + /*------------- + Channel 2 + ------------- + + If timer_mode == 0: + + SWITCHED AD7524 + NOISE ---> RC ---> 1.56x AMP ---> INVERTER ---> VRef ---> 33k ---> mix + FILTERS + + If timer mode == 1: + + AD7524 SWITCHED + NOISE ---> INVERTER ---> VRef ---> 33k ---> mix ---> INVERTER ---> RC ---> 1.56x AMP ---> finalmix + FILTERS + */ + + /* channel 2 clocks with the 2MHZ clock and triggers with the GOS clock */ + for (step = 0; step < USB_2MHZ_CLOCK / SAMPLE_RATE; step++) + { + if (g->chan[2].subcount-- == 0) + { + g->chan[2].subcount = USB_2MHZ_CLOCK / USB_GOS_CLOCK / 2 - 1; + g->chan[2].gate = !g->chan[2].gate; + } + clock_channel(&g->chan[2]); + } + + /* the exponents for the gate filters are determined by channel 2's output */ + g->gate1.exponent = m_gate_rc1_exp[g->chan[2].output]; + g->gate2.exponent = m_gate_rc2_exp[g->chan[2].output]; + + /* based on the envelope mode, we do one of two things with source 2 */ + if (g->config == 0) + { + chan2 = step_rc_filter(&g->gate2, step_rc_filter(&g->gate1, noiseval)) * -1.56 * g->env[2] * (1.0/33.0); + mix = chan0 + chan1 + chan2; + } + else + { + chan2 = -noiseval * g->env[2] * (1.0/33.0); + mix = chan0 + chan1 + chan2; + mix = step_rc_filter(&g->gate2, step_rc_filter(&g->gate1, -mix)) * 1.56; + } + + /* accumulate the sample */ + sample += mix; + } + + + /*------------- + Final mix + ------------- + + INPUTS + EQUAL ---> 1.2x INVERTER ---> CR FILTER ---> out + WEIGHT + + */ + *dest++ = 4000 * step_cr_filter(&m_final_filter, sample); + } +} + + +/************************************* + * + * USB address maps + * + *************************************/ + +static ADDRESS_MAP_START( usb_map, AS_PROGRAM, 8, usb_sound_device ) + AM_RANGE(0x0000, 0x0fff) AM_RAM AM_SHARE("pgmram") +ADDRESS_MAP_END + +static ADDRESS_MAP_START( usb_portmap, AS_IO, 8, usb_sound_device ) + AM_RANGE(0x00, 0xff) AM_READWRITE(workram_r, workram_w) AM_SHARE("workram") + AM_RANGE(MCS48_PORT_P1, MCS48_PORT_P1) AM_READWRITE(p1_r, p1_w) + AM_RANGE(MCS48_PORT_P2, MCS48_PORT_P2) AM_WRITE(p2_w) + AM_RANGE(MCS48_PORT_T1, MCS48_PORT_T1) AM_READ(t1_r) +ADDRESS_MAP_END + + +/************************************* + * + * USB machine drivers + * + *************************************/ + +MACHINE_CONFIG_FRAGMENT( segausb ) + + /* CPU for the usb board */ + MCFG_CPU_ADD("ourcpu", I8035, USB_MASTER_CLOCK) /* divide by 15 in CPU */ + MCFG_CPU_PROGRAM_MAP(usb_map) + MCFG_CPU_IO_MAP(usb_portmap) + + MCFG_TIMER_DRIVER_ADD_PERIODIC("usb_timer", usb_sound_device, increment_t1_clock_timer_cb, attotime::from_hz(USB_2MHZ_CLOCK / 256)) +MACHINE_CONFIG_END + +machine_config_constructor usb_sound_device::device_mconfig_additions() const +{ + return MACHINE_CONFIG_NAME( segausb ); +} + +const device_type SEGAUSBROM = &device_creator<usb_rom_sound_device>; + +usb_rom_sound_device::usb_rom_sound_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : usb_sound_device(mconfig, SEGAUSBROM, "Sega Universal Sound Board with ROM", tag, owner, clock, "segausbrom", __FILE__) +{ +} + +static ADDRESS_MAP_START( usb_map_rom, AS_PROGRAM, 8, usb_sound_device ) + AM_RANGE(0x0000, 0x0fff) AM_ROM AM_REGION(":usbcpu", 0) +ADDRESS_MAP_END + +MACHINE_CONFIG_FRAGMENT( segausb_rom ) + + /* CPU for the usb board */ + MCFG_CPU_ADD("ourcpu", I8035, USB_MASTER_CLOCK) /* divide by 15 in CPU */ + MCFG_CPU_PROGRAM_MAP(usb_map_rom) + MCFG_CPU_IO_MAP(usb_portmap) + + MCFG_TIMER_DRIVER_ADD_PERIODIC("usb_timer", usb_sound_device, increment_t1_clock_timer_cb, attotime::from_hz(USB_2MHZ_CLOCK / 256)) +MACHINE_CONFIG_END + +machine_config_constructor usb_rom_sound_device::device_mconfig_additions() const +{ + return MACHINE_CONFIG_NAME( segausb_rom ); +} |