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Diffstat (limited to 'trunk/src/emu/sound/tc8830f.c')
-rw-r--r-- | trunk/src/emu/sound/tc8830f.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/trunk/src/emu/sound/tc8830f.c b/trunk/src/emu/sound/tc8830f.c new file mode 100644 index 00000000000..cf855c8ee04 --- /dev/null +++ b/trunk/src/emu/sound/tc8830f.c @@ -0,0 +1,209 @@ +/*************************************************************************** + + tc8830f.c - Toshiba TC8830F, CMOS voice recording/reproducing LSI + 1-bit ADM (Adaptive Delta Modulation), similar to TC8801 and T6668. + + Very preliminary... + + TODO: + - ADM decoder + - remaining commands + - manual control + - chip read + - RAM + - recording + +***************************************************************************/ + +#include "emu.h" +#include "tc8830f.h" + + +// device type definition +const device_type TC8830F = &device_creator<tc8830f_device>; + +tc8830f_device::tc8830f_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : device_t(mconfig, TC8830F, "TC8830F", tag, owner, clock), + device_sound_interface(mconfig, *this) +{ +} + + +void tc8830f_device::device_start() +{ + // create the stream + m_stream = machine().sound().stream_alloc(*this, 0, 1, clock() / 0x10, this); + + m_mem_base = (UINT8 *)device().machine().root_device().memregion(":tc8830f")->base(); + m_mem_mask = device().machine().root_device().memregion(":tc8830f")->bytes() - 1; + + // register for savestates + save_item(NAME(m_playing)); + save_item(NAME(m_address)); + save_item(NAME(m_stop_address)); + save_item(NAME(m_bitcount)); + save_item(NAME(m_bitrate)); + save_item(NAME(m_command)); + save_item(NAME(m_cmd_rw)); + save_item(NAME(m_phrase)); + + reset(); +} + + +void tc8830f_device::device_post_load() +{ + device_clock_changed(); +} + + +void tc8830f_device::device_clock_changed() +{ + int divisor = 0x10 * (4 - (m_bitrate & 3)); + m_stream->set_sample_rate(clock() / divisor); +} + + + +void tc8830f_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples) +{ + for (int i = 0; i < samples; i++) + { + int mix = 0; + if (m_playing) + { + // get bit + int bit = m_mem_base[m_address] >> m_bitcount & 1; + m_bitcount = (m_bitcount + 1) & 7; + if (m_bitcount == 0) + { + m_address = (m_address + 1) & m_mem_mask; + if (m_address == m_stop_address) + m_playing = false; + } + + // compute sample + // this is a placeholder until ADM is implemented + mix = bit * 0x7fff; + } + outputs[0][i] = mix; + } +} + + +void tc8830f_device::reset() +{ + m_stream->update(); + + m_playing = false; + m_address = 0x100; + m_bitcount = 0; + m_cmd_rw = 0; + + // in cpu control, enter play mode and reset bitrate + write_p(1); + write_p(6); + write_p(0); +} + + +void tc8830f_device::write_p(UINT8 data) +{ + m_stream->update(); + data &= 0xf; + + if (m_cmd_rw == 0) + { + // select command + m_command = data; + switch (m_command) + { + // immediate commands + case 0x1: + break; + + case 0x2: + m_playing = true; + break; + + case 0x3: + m_playing = false; + break; + + // multi-nibble commands + case 0x4: case 0x5: case 0x6: case 0x7: + m_cmd_rw = 1; + break; + + case 0x8: case 0x9: case 0xa: case 0xb: + logerror("tc8830f: Unemulated command %X\n", m_command); + break; + + default: + logerror("tc8830f: Invalid command %X\n", m_command); + break; + } + } + + else + { + // write command + switch (m_command) + { + case 0x4: + // ADLD1: set address counter + m_address = (m_address & ~(0xf << (m_cmd_rw*4))) | (data << (m_cmd_rw*4)); + if (m_cmd_rw == 5) + { + m_address &= m_mem_mask; + m_bitcount = 0; + m_cmd_rw = -1; + } + break; + + case 0x5: + // ADLD2: set address stop + m_stop_address = (m_stop_address & ~(0xf << (m_cmd_rw*4))) | (data << (m_cmd_rw*4)); + if (m_cmd_rw == 5) + { + m_stop_address &= m_mem_mask; + m_cmd_rw = -1; + } + break; + + case 0x6: + // CNDT: d0-d1: bitrate, d2: enable overflow + m_bitrate = data & 3; + device_clock_changed(); + m_cmd_rw = -1; + break; + + case 0x7: + // LABEL: set phrase + if (m_cmd_rw == 1) + { + m_phrase = (m_phrase & 0x30) | data; + } + else + { + m_phrase = (m_phrase & 0x0f) | (data << 4 & 0x30); + + // update addresses and start + UINT8 offs = m_phrase * 4; + m_address = (m_mem_base[offs] | m_mem_base[offs|1]<<8 | m_mem_base[offs|2]<<16) & m_mem_mask; + offs += 4; + m_stop_address = (m_mem_base[offs] | m_mem_base[offs|1]<<8 | m_mem_base[offs|2]<<16) & m_mem_mask; + + m_bitcount = 0; + m_playing = true; + m_cmd_rw = -1; + } + break; + + default: + m_cmd_rw = -1; + break; + } + m_cmd_rw++; + } +} |