// license:BSD-3-Clause // copyright-holders:Olivier Galibert // Custom Thomson 3.5"/5.25"/QDD diskette controller gate array used in CD 90-351, TO8 and TO9+ #include "emu.h" #include "thmfc1.h" DEFINE_DEVICE_TYPE(THMFC1, thmfc1_device, "thmfc1", "SGS-Thomson THM-FC-1 Diskette Controller") // SGS logo used on silkscreen thmfc1_device::thmfc1_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, THMFC1, tag, owner, clock), m_floppy(*this, "%u", 0U) { } void thmfc1_device::map(address_map &map) { map(0, 0).rw(FUNC(thmfc1_device::stat0_r), FUNC(thmfc1_device::cmd0_w)); map(1, 1).rw(FUNC(thmfc1_device::stat1_r), FUNC(thmfc1_device::cmd1_w)); map(2, 2).w(FUNC(thmfc1_device::cmd2_w)); map(3, 3).rw(FUNC(thmfc1_device::rdata_r), FUNC(thmfc1_device::wdata_w)); map(4, 4).w(FUNC(thmfc1_device::wclk_w)); map(5, 5).w(FUNC(thmfc1_device::wsect_w)); map(6, 6).w(FUNC(thmfc1_device::wtrck_w)); map(7, 7).w(FUNC(thmfc1_device::wcell_w)); } void thmfc1_device::device_start() { m_timer_motoroff = timer_alloc(FUNC(thmfc1_device::motor_off), this); save_item(NAME(m_cmd0)); save_item(NAME(m_cmd1)); save_item(NAME(m_cmd2)); save_item(NAME(m_stat0)); save_item(NAME(m_data)); save_item(NAME(m_clk)); save_item(NAME(m_sect)); save_item(NAME(m_trck)); save_item(NAME(m_cell)); save_item(NAME(m_last_sync)); save_item(NAME(m_window_start)); save_item(NAME(m_shift_reg)); save_item(NAME(m_crc)); save_item(NAME(m_bit_counter)); save_item(NAME(m_data_reg)); save_item(NAME(m_data_separator_phase)); } void thmfc1_device::device_reset() { m_cmd0 = 0; m_cmd1 = 0; m_cmd2 = 0; m_stat0 = S0_FREE; m_data = 0; m_clk = 0; m_sect = 0; m_trck = 0; m_cell = 0; m_last_sync = 0; m_window_start = 0; m_shift_reg = 0; m_crc = 0; m_bit_counter = 0; m_data_reg = 0; m_data_separator_phase = false; m_state = S_IDLE; m_cur_floppy = nullptr; } TIMER_CALLBACK_MEMBER(thmfc1_device::motor_off) { logerror("motor off\n"); if(m_cur_floppy) m_cur_floppy->mon_w(1); } void thmfc1_device::device_post_load() { if(m_cmd2 & C2_DRS0) m_cur_floppy = m_floppy[0]->get_device(); else if(m_cmd2 & C2_DRS1) m_cur_floppy = m_floppy[1]->get_device(); else m_cur_floppy = nullptr; } void thmfc1_device::cmd0_w(u8 data) { sync(); static const char *const mode[4] = { "reset", "wsect", "rhead", "rsect" }; m_cmd0 = data; logerror("cmd0_w %02x, code=%s, ensyn=%d nomck=%d wgc=%d mode=%s\n", m_cmd0, m_cmd0 & C0_FM ? "fm" : "mfm", m_cmd0 & C0_ENSYN ? 1 : 0, m_cmd0 & C0_NOMCK ? 1 : 0, m_cmd0 & C0_WGC ? 1 : 0, mode[m_cmd0 & 3]); if(m_stat0 & S0_FREE) { switch(m_cmd0 & 3) { case 0: break; case 1: logerror("wsect\n"); exit(0); case 2: logerror("rhead\n"); exit(0); case 3: logerror("read_sector start h=%d t=%2d s=%2d sz=%d\n", m_cmd1 & C1_SIDE ? 1 : 0, m_trck, m_sect, 128 << ((m_cmd1 >> 5) & 3)); m_state = S_WAIT_HEADER_SYNC; m_stat0 &= ~S0_FREE; m_window_start = m_last_sync; break; } } } void thmfc1_device::cmd1_w(u8 data) { sync(); m_cmd1 = data; logerror("cmd1_w %02x, sector=(size=%d, side=%d) precomp=%d sync_only_when_ready=%s\n", m_cmd1, 128 << ((m_cmd1 >> 5) & 3), m_cmd1 & C1_SIDE ? 1 : 0, (m_cmd1 >> 1) & 7, m_cmd1 & C1_DSYRD ? "on" : "off"); } void thmfc1_device::cmd2_w(u8 data) { sync(); u8 prev = m_cmd2; m_cmd2 = data; logerror("cmd2_w %02x, side=%d dir=%d step=%d motor=%s sel=%c%c\n", m_cmd2, m_cmd2 & C2_SISELB ? 1 : 0, m_cmd2 & C2_DIRECB ? 1 : 0, m_cmd2 & C2_STEP ? 1 : 0, m_cmd2 & C2_MTON ? "on" : "off", m_cmd2 & C2_DRS1 ? 'b' : '-', m_cmd2 & C2_DRS0 ? 'a' : '-'); if(m_cmd2 & C2_DRS0) m_cur_floppy = m_floppy[0]->get_device(); else if(m_cmd2 & C2_DRS1) m_cur_floppy = m_floppy[1]->get_device(); else m_cur_floppy = nullptr; if(m_cur_floppy) { if((prev & C2_MTON) && !(m_cmd2 & C2_MTON)) m_timer_motoroff->adjust(attotime::from_seconds(2)); if(m_cmd2 & C2_MTON) { m_cur_floppy->mon_w(0); m_timer_motoroff->adjust(attotime::never); } m_cur_floppy->ss_w(m_cmd2 & C2_SISELB ? 0 : 1); m_cur_floppy->dir_w(m_cmd2 & C2_DIRECB ? 0 : 1); m_cur_floppy->stp_w(m_cmd2 & C2_STEP ? 0 : 1); } } void thmfc1_device::wdata_w(u8 data) { m_data = data; m_stat0 &= ~(S0_BYTE | S0_DREQ); logerror("wdata_w %02x\n", data); } void thmfc1_device::wclk_w(u8 data) { sync(); m_clk = data; logerror("wclk_w %02x\n", data); } void thmfc1_device::wsect_w(u8 data) { sync(); m_sect = data; logerror("wsect_w %02x\n", data); } void thmfc1_device::wtrck_w(u8 data) { sync(); m_trck = data; logerror("wtrck_w %02x\n", data); } void thmfc1_device::wcell_w(u8 data) { sync(); m_cell = data; logerror("wcell_w %02x\n", data); } u8 thmfc1_device::stat0_r() { if(!machine().side_effects_disabled()) { sync(); #if 0 static int ps = -1; if(m_stat0 != ps) logerror("stat0_r %02x -%s%s%s%s%s%s\n", m_stat0, m_stat0 & S0_BYTE ? " byte" : "", m_stat0 & S0_END ? " end" : "", m_stat0 & S0_FREE ? " free" : "", m_stat0 & S0_CRCER ? " crcer" : "", m_stat0 & S0_DREQ ? " dreq" : "", m_stat0 & S0_SYNC ? " sync" : ""); ps = m_stat0; #endif } return m_stat0; } u8 thmfc1_device::stat1_r() { u8 res = 0; if(m_cur_floppy) { if(m_cur_floppy->idx_r()) res |= S1_INDX; if(!m_cur_floppy->dskchg_r()) res |= S1_DKCH; if(!m_cur_floppy->mon_r()) res |= S1_MTON; if(!m_cur_floppy->trk00_r()) res |= S1_TRK0; if(!m_cur_floppy->wpt_r()) res |= S1_WPRT; if(!m_cur_floppy->ready_r()) res |= S1_RDY; } if(!machine().side_effects_disabled()) logerror("stat1_r %02x -%s%s%s%s%s%s\n", res, res & S1_INDX ? " index" : "", res & S1_DKCH ? " dskchg" : "", res & S1_MTON ? " mton" : "", res & S1_TRK0 ? " trk0" : "", res & S1_WPRT ? " wprt" : "", res & S1_RDY ? " ready" : ""); return res; } u8 thmfc1_device::rdata_r() { if(!machine().side_effects_disabled()) { logerror("rdata_r %02X (stat0=%02X)\n", m_data, m_stat0); m_stat0 &= ~(S0_BYTE | S0_DREQ); } return m_data; } u64 thmfc1_device::time_to_cycles(const attotime &tm) const { return tm.as_ticks(clock()); } attotime thmfc1_device::cycles_to_time(u64 cycles) const { return attotime::from_ticks(cycles, clock()); } bool thmfc1_device::read_one_bit(u64 limit, u64 &next_flux_change) { while(next_flux_change <= m_last_sync) { attotime flux = m_cur_floppy ? m_cur_floppy->get_next_transition(cycles_to_time(m_last_sync+1)) : attotime::never; next_flux_change = flux.is_never() ? u64(-1) : time_to_cycles(flux); } u64 window_end = m_window_start + (m_cell & 0x7f); if(window_end > limit) return true; int bit = next_flux_change < window_end; if(bit && (m_cmd0 & C0_NOMCK)) m_window_start = next_flux_change + ((m_cell & 0x7f) >> 1); else m_window_start = window_end; m_last_sync = window_end; m_shift_reg = (m_shift_reg << 1) | bit; m_bit_counter++; if(m_data_separator_phase) { m_data_reg = (m_data_reg << 1) | bit; if((m_crc ^ (bit ? 0x8000 : 0x0000)) & 0x8000) m_crc = (m_crc << 1) ^ 0x1021; else m_crc = m_crc << 1; } m_data_separator_phase = !m_data_separator_phase; return false; } u8 thmfc1_device::clk_bits() const { return (m_shift_reg & 0x8000 ? 0x80 : 0x00) | (m_shift_reg & 0x2000 ? 0x40 : 0x00) | (m_shift_reg & 0x0800 ? 0x20 : 0x00) | (m_shift_reg & 0x0200 ? 0x10 : 0x00) | (m_shift_reg & 0x0080 ? 0x08 : 0x00) | (m_shift_reg & 0x0020 ? 0x04 : 0x00) | (m_shift_reg & 0x0008 ? 0x02 : 0x00) | (m_shift_reg & 0x0002 ? 0x01 : 0x00); } void thmfc1_device::sync() { u64 next_sync = machine().time().as_ticks(clock()); u64 next_flux_change = 0; while(m_last_sync < next_sync) switch(m_state) { case S_IDLE: m_last_sync = next_sync; break; case S_WAIT_HEADER_SYNC: { if(read_one_bit(next_sync, next_flux_change)) return; if(m_shift_reg == 0xaaaa) { m_crc = 0xffff; m_data_separator_phase = false; } if(m_data_reg == m_data && clk_bits() == m_clk) { m_bit_counter = 0; m_state = S_VERIFY_HEADER; } break; } case S_VERIFY_HEADER: { if(read_one_bit(next_sync, next_flux_change)) return; if(m_bit_counter & 0xf) break; bool valid = true; switch(m_bit_counter >> 4) { case 1: case 2: valid = m_data_reg == m_data && clk_bits() == m_clk; break; case 3: valid = m_data_reg == 0xfe; break; case 4: valid = m_data_reg == m_trck; break; case 5: // C1_SIDE seems to be ignored here, at least for floppy disks valid = (m_data_reg & 1) == (m_cmd2 & C2_SISELB ? 0 : 1); break; case 6: valid = m_data_reg == m_sect; break; case 7: valid = (m_data_reg & 3) == ((m_cmd1 >> 5) & 3); break; // 8 skipped case 9: valid = m_crc == 0; m_bit_counter = 0; m_state = S_SKIP_GAP; break; } if(!valid) m_state = S_WAIT_HEADER_SYNC; break; } case S_SKIP_GAP: if(read_one_bit(next_sync, next_flux_change)) return; if(m_bit_counter == 27 << 4) { m_bit_counter = 0; m_state = S_WAIT_SECTOR_SYNC; } break; case S_WAIT_SECTOR_SYNC: { if(read_one_bit(next_sync, next_flux_change)) return; if(m_shift_reg == 0xaaaa) { m_crc = 0xffff; m_data_separator_phase = false; } if(m_data_reg == m_data && clk_bits() == m_clk) { m_bit_counter = 0; m_data = m_data_reg; m_stat0 |= S0_DREQ; m_state = S_READ_SECTOR; } if(m_bit_counter == 42 << 4) m_state = S_WAIT_HEADER_SYNC; break; } case S_READ_SECTOR: if(read_one_bit(next_sync, next_flux_change)) return; if(m_bit_counter != 16) break; if(m_stat0 & (S0_BYTE|S0_DREQ)) { logerror("read_sector end\n"); if(m_crc) m_stat0 |= S0_CRCER; m_stat0 &= ~S0_BYTE; m_stat0 |= S0_FREE; m_cmd0 &= ~3; m_state = S_IDLE; break; } m_stat0 |= S0_BYTE; m_data = m_data_reg; m_bit_counter = 0; break; } }