mame/src/devices/cpu/sm510/sm510.cpp
2017-04-30 10:59:05 +02:00

321 lines
7.6 KiB
C++

// license:BSD-3-Clause
// copyright-holders:hap
/*
Known chips: (* means not emulated yet)
Sharp SM510 MCU family:
- SM510: 2.7Kx8 ROM, 128x4 RAM(32x4 for LCD)
- SM511: 4Kx8 ROM, 128x4 RAM(32x4 for LCD), melody controller
- SM512: 4Kx8 ROM, 128x4 RAM(48x4 for LCD), melody controller
- *KB1013VK4-2: Soviet-era clone of SM510, minor differences
Sharp SM500 MCU family:
- *SM500: x
- *SM4A: x
- *SM530: x
- *SM531: x
- *KB1013VK1-2: Soviet-era clone of SM500, minor differences
References:
- 1990 Sharp Microcomputers Data Book
- 1996 Sharp Microcomputer Databook
- KB1013VK1-2/KB1013VK4-2 manual
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 (0.5s off, 0.5s on)
- SM510 buzzer control divider bit is mask-programmable?
- SM511 undocumented/guessed opcodes:
* $01 is guessed as DIV to ACC transfer, unknown which bits
* $5d is certainly CEND
* $65 is certainly divider reset, but not sure if it behaves same as on SM510
* $6036 may be instruction timing? (16KHz vs 8KHz)
*/
#include "emu.h"
#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_sbm = false;
m_c = 0;
m_skip = false;
m_w = 0;
m_r = 0;
m_r_out = 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_sbm));
save_item(NAME(m_c));
save_item(NAME(m_skip));
save_item(NAME(m_w));
save_item(NAME(m_r));
save_item(NAME(m_r_out));
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, "GENPC", m_pc).formatstr("%04X").noshow();
state_add(STATE_GENPCBASE, "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()
{
// ACL
m_skip = false;
m_halt = false;
m_sbm = 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 = m_r_out = 0;
m_write_r(0, 0, 0xff);
m_melody_rd &= ~1;
}
//-------------------------------------------------
// lcd driver
//-------------------------------------------------
inline u16 sm510_base_device::get_lcd_row(int column, u8* ram)
{
// output 0 if lcd blackpate/bleeder is off, or in case row doesn't exist
if (ram == nullptr || m_bc || !m_bp)
return 0;
u16 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
u8 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
}
//-------------------------------------------------
// 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();
}
}