mame/src/devices/machine/pcf8573.cpp
2022-05-22 09:36:01 +10:00

361 lines
7.8 KiB
C++

// license:BSD-3-Clause
// copyright-holders:Nigel Barnes
/*********************************************************************
Philips PCF8573 Clock and Calendar with Power Fail Detector
TODO:
- status bits 3/4 seconds/minutes are not set.
*********************************************************************/
#include "emu.h"
#include "pcf8573.h"
#define LOG_DATA (1 << 1)
#define LOG_LINE (1 << 2)
#define VERBOSE (0)
#include "logmacro.h"
DEFINE_DEVICE_TYPE(PCF8573, pcf8573_device, "pcf8573", "PCF8573 RTC with Power Fail Detector")
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
//-------------------------------------------------
// pcf8573_device - constructor
//-------------------------------------------------
pcf8573_device::pcf8573_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: device_t(mconfig, PCF8573, tag, owner, clock)
, device_rtc_interface(mconfig, *this)
, m_comp_cb(*this)
, m_min_cb(*this)
, m_sec_cb(*this)
, m_clock_timer(nullptr)
, m_slave_address(PCF8573_SLAVE_ADDRESS)
, m_scl(0)
, m_sdaw(0)
, m_sdar(1)
, m_state(STATE_IDLE)
, m_bits(0)
, m_shift(0)
, m_devsel(0)
, m_mode_pointer(0)
, m_address(0)
, m_status(0)
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void pcf8573_device::device_start()
{
m_comp_cb.resolve_safe();
m_min_cb.resolve_safe();
m_sec_cb.resolve_safe();
// allocate timers
m_clock_timer = timer_alloc();
m_clock_timer->adjust(attotime::from_hz(clock() / 32768), 0, attotime::from_hz(clock() / 32768));
// state saving
save_item(NAME(m_scl));
save_item(NAME(m_sdaw));
save_item(NAME(m_sdar));
save_item(NAME(m_state));
save_item(NAME(m_bits));
save_item(NAME(m_shift));
save_item(NAME(m_devsel));
save_item(NAME(m_mode_pointer));
save_item(NAME(m_address));
save_item(NAME(m_status));
save_item(NAME(m_data));
save_item(NAME(m_slave_address));
}
//-------------------------------------------------
// device_timer - handler timer events
//-------------------------------------------------
void pcf8573_device::device_timer(emu_timer &timer, device_timer_id id, int param)
{
advance_seconds();
// one pulse per second output
m_sec_cb(1);
m_sec_cb(0);
}
void pcf8573_device::rtc_clock_updated(int year, int month, int day, int day_of_week, int hour, int minute, int second)
{
if (m_data[REG_MINUTES] == convert_to_bcd(minute))
return;
// update registers
set_time_minute(minute);
set_time_hour(hour);
set_date_day(day);
set_date_month(month);
// one pulse per minute output
m_min_cb(1);
m_min_cb(0);
// comparator output
if (m_data[REG_HOURS] == m_data[REG_ALARM_HOURS] && m_data[REG_MINUTES] == m_data[REG_ALARM_MINUTES])
{
if (BIT(m_status, 2) || (m_data[REG_DAYS] == m_data[REG_ALARM_DAYS] && m_data[REG_MONTHS] == m_data[REG_ALARM_MONTHS]))
{
// set COMP flag
m_status |= 1 << 1;
m_comp_cb(1);
}
}
}
//**************************************************************************
// READ/WRITE HANDLERS
//**************************************************************************
WRITE_LINE_MEMBER(pcf8573_device::a0_w)
{
state &= 1;
if (BIT(m_slave_address, 1) != state)
{
LOGMASKED(LOG_LINE, "set a0 %d\n", state );
m_slave_address = (m_slave_address & 0xfd) | (state << 1);
}
}
WRITE_LINE_MEMBER(pcf8573_device::a1_w)
{
state &= 1;
if (BIT(m_slave_address, 2) != state)
{
LOGMASKED(LOG_LINE, "set a1 %d\n", state );
m_slave_address = (m_slave_address & 0xfb) | (state << 2);
}
}
WRITE_LINE_MEMBER(pcf8573_device::scl_w)
{
if (m_scl != state)
{
m_scl = state;
LOGMASKED(LOG_LINE, "set_scl_line %d\n", m_scl);
switch (m_state)
{
case STATE_ADDRESS:
case STATE_MODE:
case STATE_DATAIN:
if (m_bits < 8)
{
if (m_scl)
{
m_shift = ((m_shift << 1) | m_sdaw) & 0xff;
m_bits++;
}
}
else
{
if (m_scl)
{
m_bits++;
}
else
{
if (m_bits == 8)
{
switch (m_state)
{
case STATE_ADDRESS:
m_devsel = m_shift;
if ((m_devsel & 0xfe) != m_slave_address)
{
LOGMASKED(LOG_DATA, "address %02x: not this device\n", m_devsel);
m_state = STATE_IDLE;
}
else if ((m_devsel & 1) == 0)
{
LOGMASKED(LOG_DATA, "address %02x: write\n", m_devsel);
m_state = STATE_MODE;
}
else
{
LOGMASKED(LOG_DATA, "address %02x: read\n", m_devsel);
m_state = STATE_READSELACK;
}
break;
case STATE_MODE:
m_mode_pointer = m_shift;
LOGMASKED(LOG_DATA, "mode pointer %02x\n", m_shift);
switch (m_mode_pointer & 0x70)
{
case 0x00: // execute address
m_address = m_mode_pointer & 0x07;
break;
case 0x10: // read control/status flags
break;
case 0x20: // reset prescaler
set_clock_register(RTC_SECOND, 0);
adjust_seconds();
break;
case 0x30: // time adjust
adjust_seconds();
break;
case 0x40: // reset NODA flag
m_status &= ~(1 << 2);
break;
case 0x50: // set NODA flag
m_status |= 1 << 2;
break;
case 0x60: // reset COMP flag
m_status &= ~(1 << 1);
m_comp_cb(0);
break;
}
m_state = STATE_DATAIN;
break;
case STATE_DATAIN:
switch (m_mode_pointer & 0x70)
{
case 0x00: // execute address
m_data[m_address] = m_shift;
LOGMASKED(LOG_DATA, "data[ %02x ] <- %02x\n", m_address, m_shift);
switch (m_address)
{
case REG_HOURS: set_clock_register(RTC_HOUR, bcd_to_integer(m_data[REG_HOURS])); break;
case REG_MINUTES: set_clock_register(RTC_MINUTE, bcd_to_integer(m_data[REG_MINUTES])); break;
case REG_DAYS: set_clock_register(RTC_DAY, bcd_to_integer(m_data[REG_DAYS])); break;
case REG_MONTHS: set_clock_register(RTC_MONTH, bcd_to_integer(m_data[REG_MONTHS])); break;
}
m_address = (m_address & 0x04) | ((m_address + 1) & 0x03);
break;
}
break;
}
if( m_state != STATE_IDLE )
{
m_sdar = 0 ;
}
}
else
{
m_bits = 0;
m_sdar = 1;
}
}
}
break;
case STATE_READSELACK:
m_bits = 0;
m_state = STATE_DATAOUT;
break;
case STATE_DATAOUT:
if (m_bits < 8)
{
if (m_scl)
{
m_bits++;
}
else
{
if (m_bits == 0)
{
switch (m_mode_pointer & 0x70)
{
case 0x00: // execute address
m_shift = m_data[m_address];
LOGMASKED(LOG_DATA, "data[ %02x ] -> %02x\n", m_address, m_shift);
m_address = (m_address & 0x04) | ((m_address + 1) & 0x03);
break;
case 0x10: // read control/status flags
m_shift = m_status;
LOGMASKED(LOG_DATA, "status -> %02x\n", m_address, m_shift);
break;
}
}
m_sdar = (m_shift >> 7) & 1;
m_shift = (m_shift << 1) & 0xff;
}
}
else
{
if (m_scl)
{
if (m_sdaw)
{
LOGMASKED(LOG_DATA, "nack\n");
m_state = STATE_IDLE;
}
m_bits = 0;
}
else
{
m_sdar = 1;
}
}
break;
}
}
}
WRITE_LINE_MEMBER(pcf8573_device::sda_w)
{
state &= 1;
if (m_sdaw != state)
{
LOGMASKED(LOG_LINE, "set sda %d\n", state);
m_sdaw = state;
if (m_scl)
{
if (m_sdaw)
{
LOGMASKED(LOG_DATA, "stop\n");
m_state = STATE_IDLE;
}
else
{
LOGMASKED(LOG_DATA, "start\n");
m_state = STATE_ADDRESS;
m_bits = 0;
}
m_sdar = 1;
}
}
}
READ_LINE_MEMBER(pcf8573_device::sda_r)
{
int res = m_sdar & 1;
LOGMASKED(LOG_LINE, "read sda %d\n", res);
return res;
}