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-rw-r--r--src/devices/machine/pcf8573.cpp356
1 files changed, 356 insertions, 0 deletions
diff --git a/src/devices/machine/pcf8573.cpp b/src/devices/machine/pcf8573.cpp
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+++ b/src/devices/machine/pcf8573.cpp
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+// 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 (1U << 1)
+#define LOG_LINE (1U << 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()
+{
+ // allocate timers
+ m_clock_timer = timer_alloc(FUNC(pcf8573_device::clock_tick), this);
+ 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));
+}
+
+//-------------------------------------------------
+// clock_tick - advance the RTC
+//-------------------------------------------------
+
+TIMER_CALLBACK_MEMBER(pcf8573_device::clock_tick)
+{
+ 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
+//**************************************************************************
+
+void pcf8573_device::a0_w(int state)
+{
+ 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);
+ }
+}
+
+void pcf8573_device::a1_w(int state)
+{
+ 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);
+ }
+}
+
+void pcf8573_device::scl_w(int state)
+{
+ 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;
+ }
+ }
+}
+
+void pcf8573_device::sda_w(int state)
+{
+ 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;
+ }
+ }
+}
+
+int pcf8573_device::sda_r()
+{
+ int res = m_sdar & 1;
+
+ LOGMASKED(LOG_LINE, "read sda %d\n", res);
+
+ return res;
+}