// license:BSD-3-Clause // copyright-holders:hap /* Sharp SM510 MCU family - known chips: - SM510: x - SM511: x - SM512: x Other chips that may be in the same family, investigate more when one of them needs to get emulated: SM500, SM530, SM531, .. References: - 1990 Sharp Microcomputers Data Book - 1996 Sharp Microcomputer Databook TODO: - proper support for LFSR program counter in debugger - callback for lcd screen as MAME bitmap (when needed) - LCD bs pin blink mode via Y register - LB opcode - SM511 unknown opcodes */ #include "sm510.h" #include "debugger.h" //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- enum { SM510_PC=1, SM510_ACC, SM510_BL, SM510_BM, SM510_C, SM510_W }; void sm510_base_device::device_start() { m_program = &space(AS_PROGRAM); m_data = &space(AS_DATA); m_prgmask = (1 << m_prgwidth) - 1; m_datamask = (1 << m_datawidth) - 1; // resolve callbacks m_read_k.resolve_safe(0); m_read_ba.resolve_safe(1); m_read_b.resolve_safe(1); m_write_s.resolve_safe(); m_write_r.resolve_safe(); m_write_sega.resolve_safe(); m_write_segb.resolve_safe(); m_write_segbs.resolve_safe(); m_write_segc.resolve_safe(); // zerofill memset(m_stack, 0, sizeof(m_stack)); m_pc = 0; m_prev_pc = 0; m_op = 0; m_prev_op = 0; m_param = 0; m_acc = 0; m_bl = 0; m_bm = 0; m_c = 0; m_skip = false; m_w = 0; m_r = 0; m_div = 0; m_1s = false; m_k_active = false; m_l = 0; m_x = 0; m_y = 0; m_bp = false; m_bc = false; m_halt = false; m_melody_rd = 0; m_melody_step_count = 0; m_melody_duty_count = 0; m_melody_duty_index = 0; m_melody_address = 0; // register for savestates save_item(NAME(m_stack)); save_item(NAME(m_pc)); save_item(NAME(m_prev_pc)); save_item(NAME(m_op)); save_item(NAME(m_prev_op)); save_item(NAME(m_param)); save_item(NAME(m_acc)); save_item(NAME(m_bl)); save_item(NAME(m_bm)); save_item(NAME(m_c)); save_item(NAME(m_skip)); save_item(NAME(m_w)); save_item(NAME(m_r)); save_item(NAME(m_div)); save_item(NAME(m_1s)); save_item(NAME(m_k_active)); save_item(NAME(m_l)); save_item(NAME(m_x)); save_item(NAME(m_y)); save_item(NAME(m_bp)); save_item(NAME(m_bc)); save_item(NAME(m_halt)); save_item(NAME(m_melody_rd)); save_item(NAME(m_melody_step_count)); save_item(NAME(m_melody_duty_count)); save_item(NAME(m_melody_duty_index)); save_item(NAME(m_melody_address)); // register state for debugger state_add(SM510_PC, "PC", m_pc).formatstr("%04X"); state_add(SM510_ACC, "ACC", m_acc).formatstr("%01X"); state_add(SM510_BL, "BL", m_bl).formatstr("%01X"); state_add(SM510_BM, "BM", m_bm).formatstr("%01X"); state_add(SM510_C, "C", m_c).formatstr("%01X"); state_add(SM510_W, "W", m_w).formatstr("%02X"); state_add(STATE_GENPC, "curpc", m_pc).formatstr("%04X").noshow(); state_add(STATE_GENFLAGS, "GENFLAGS", m_c).formatstr("%1s").noshow(); m_icountptr = &m_icount; // init peripherals init_divider(); init_lcd_driver(); init_melody(); } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void sm510_base_device::device_reset() { m_skip = false; m_halt = false; m_op = m_prev_op = 0; do_branch(3, 7, 0); m_prev_pc = m_pc; // lcd is on (Bp on, BC off, bs(y) off) m_bp = true; m_bc = false; m_y = 0; m_r = 0; m_write_r(0, 0, 0xff); m_melody_rd &= ~1; } //------------------------------------------------- // lcd driver //------------------------------------------------- inline UINT16 sm510_base_device::get_lcd_row(int column, UINT8* ram) { // output 0 if lcd blackpate/bleeder is off, or in case row doesn't exist if (ram == NULL || m_bc || !m_bp) return 0; UINT16 rowdata = 0; for (int i = 0; i < 0x10; i++) rowdata |= (ram[i] >> column & 1) << i; return rowdata; } TIMER_CALLBACK_MEMBER(sm510_base_device::lcd_timer_cb) { // 4 columns for (int h = 0; h < 4; h++) { // 16 segments per row from upper part of RAM m_write_sega(h | SM510_PORT_SEGA, get_lcd_row(h, m_lcd_ram_a), 0xffff); m_write_segb(h | SM510_PORT_SEGB, get_lcd_row(h, m_lcd_ram_b), 0xffff); m_write_segc(h | SM510_PORT_SEGC, get_lcd_row(h, m_lcd_ram_c), 0xffff); // bs output from L/X and Y regs UINT8 bs = (m_l >> h & 1) | ((m_x*2) >> h & 2); m_write_segbs(h | SM510_PORT_SEGBS, (m_bc || !m_bp) ? 0 : bs, 0xffff); } // schedule next timeout m_lcd_timer->adjust(attotime::from_ticks(0x200, unscaled_clock())); } void sm510_base_device::init_lcd_driver() { // note: in reality, this timer runs at high frequency off the main divider, strobing one segment at a time m_lcd_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(sm510_base_device::lcd_timer_cb), this)); m_lcd_timer->adjust(attotime::from_ticks(0x200, unscaled_clock())); // 64hz default } //------------------------------------------------- // melody controller //------------------------------------------------- void sm510_base_device::clock_melody() { if (!m_melody_rom) return; // tone cycle table (SM511/SM512 datasheet fig.5) // cmd 0 = cmd, 1 = stop, > 13 = illegal(unknown) static const UINT8 lut_tone_cycles[4*16] = { 0, 0, 7, 8, 8, 9, 9, 10,11,11,12,13,14,14, 7*2, 8*2, 0, 0, 8, 8, 9, 9, 10,11,11,12,13,13,14,15, 8*2, 8*2, 0, 0, 8, 8, 9, 9, 10,10,11,12,12,13,14,15, 8*2, 8*2, 0, 0, 8, 9, 9, 10,10,11,11,12,13,14,14,15, 8*2, 9*2 }; UINT8 cmd = m_melody_rom[m_melody_address] & 0x3f; UINT8 out = 0; // clock duty cycle if tone is active if ((cmd & 0xf) > 1) { out = m_melody_duty_index & m_melody_rd & 1; m_melody_duty_count++; int index = m_melody_duty_index << 4 | (cmd & 0xf); int shift = ~cmd >> 4 & 1; // OCT if (m_melody_duty_count >= (lut_tone_cycles[index] << shift)) { m_melody_duty_count = 0; m_melody_duty_index = (m_melody_duty_index + 1) & 3; } } else if ((cmd & 0xf) == 1) { // rest tell signal m_melody_rd |= 2; } // clock time base on F8(d7) if ((m_div & 0x7f) == 0) { UINT8 mask = (cmd & 0x20) ? 0x1f : 0x0f; m_melody_step_count = (m_melody_step_count + 1) & mask; if (m_melody_step_count == 0) m_melody_address++; } // output to R pin if (out != m_r) { m_write_r(0, out, 0xff); m_r = out; } } void sm510_base_device::init_melody() { if (!m_melody_rom) return; // verify melody rom for (int i = 0; i < 0x100; i++) { UINT8 data = m_melody_rom[i]; if (data & 0xc0 || (data & 0x0f) > 13) logerror("%s unknown melody ROM data $%02X at $%02X\n", tag(), data, i); } } //------------------------------------------------- // interrupt/divider //------------------------------------------------- bool sm510_base_device::wake_me_up() { // in halt mode, wake up after 1S signal or K input if (m_k_active || m_1s) { // note: official doc warns that Bl/Bm and the stack are undefined // after waking up, but we leave it unchanged m_halt = false; do_branch(1, 0, 0); standard_irq_callback(0); return true; } else return false; } void sm510_base_device::execute_set_input(int line, int state) { if (line != SM510_INPUT_LINE_K) return; // set K input lines active state m_k_active = (state != 0); } TIMER_CALLBACK_MEMBER(sm510_base_device::div_timer_cb) { m_div = (m_div + 1) & 0x7fff; // 1S signal on overflow(falling edge of f1) if (m_div == 0) m_1s = true; clock_melody(); } void sm510_base_device::init_divider() { m_div_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(sm510_base_device::div_timer_cb), this)); m_div_timer->adjust(attotime::from_ticks(1, unscaled_clock()), 0, attotime::from_ticks(1, unscaled_clock())); } //------------------------------------------------- // execute //------------------------------------------------- void sm510_base_device::increment_pc() { // PL(program counter low 6 bits) is a simple LFSR: newbit = (bit0==bit1) // PU,PM(high bits) specify page, PL specifies steps within page int feed = ((m_pc >> 1 ^ m_pc) & 1) ? 0 : 0x20; m_pc = feed | (m_pc >> 1 & 0x1f) | (m_pc & ~0x3f); } void sm510_base_device::execute_run() { while (m_icount > 0) { m_icount--; if (m_halt && !wake_me_up()) { // got nothing to do m_icount = 0; return; } // remember previous state m_prev_op = m_op; m_prev_pc = m_pc; // fetch next opcode debugger_instruction_hook(this, m_pc); m_op = m_program->read_byte(m_pc); increment_pc(); get_opcode_param(); // handle opcode if it's not skipped if (m_skip) { m_skip = false; m_op = 0; // fake nop } else execute_one(); } }