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author Michael Zapf <github@mizapf.de>2020-06-20 23:22:59 +0200
committer Michael Zapf <github@mizapf.de>2020-06-20 23:24:29 +0200
commit627b2d6192857d69fb540260f75ecdca42179373 (patch)
treeab916bacc3dcaa96501c4517445ba584ad268892
parent36166c0b453a4c043b61f96bd31647e7d6047e36 (diff)
bq48x2: Derive clock chip from device_rtc_interface.
-rw-r--r--src/devices/machine/bq4847.cpp1
-rw-r--r--src/devices/machine/bq48x2.cpp117
-rw-r--r--src/devices/machine/bq48x2.h21
3 files changed, 76 insertions, 63 deletions
diff --git a/src/devices/machine/bq4847.cpp b/src/devices/machine/bq4847.cpp
index 3c0ec0c1e94..09afd9b9424 100644
--- a/src/devices/machine/bq4847.cpp
+++ b/src/devices/machine/bq4847.cpp
@@ -535,7 +535,6 @@ void bq4847_device::nvram_default()
void bq4847_device::nvram_read(emu_file &file)
{
file.read(m_reg, 16);
- // get_system_time();
transfer_to_access();
// Clear the saved flags
diff --git a/src/devices/machine/bq48x2.cpp b/src/devices/machine/bq48x2.cpp
index dbfb1240357..40bfde5a754 100644
--- a/src/devices/machine/bq48x2.cpp
+++ b/src/devices/machine/bq48x2.cpp
@@ -17,9 +17,6 @@
#define VERBOSE ( LOG_GENERAL | LOG_WARN )
#include "logmacro.h"
-// Need to check whether these chips really support leap year handling
-#define DOLEAPYEARS 1
-
// device type definition
DEFINE_DEVICE_TYPE(BQ4842, bq4842_device, "bq4842", "Benchmarq BQ4842 RTC")
DEFINE_DEVICE_TYPE(BQ4852, bq4852_device, "bq4852", "Benchmarq BQ4852 RTC")
@@ -65,6 +62,7 @@ enum
bq48x2_device::bq48x2_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, int memsize)
: device_t(mconfig, type, tag, owner, 0),
device_nvram_interface(mconfig, *this),
+ device_rtc_interface(mconfig, *this),
m_interrupt_cb(*this),
m_resetout_cb(*this),
m_memsize(memsize)
@@ -87,6 +85,21 @@ bq4852_device::bq4852_device(const machine_config &mconfig, const char *tag, dev
{
}
+/*
+ Inherited from device_rtc_interface. The date and time is given as integer
+ and must be converted to BCD.
+*/
+void bq48x2_device::rtc_clock_updated(int year, int month, int day, int day_of_week, int hour, int minute, int second)
+{
+ m_intreg[reg_hours] = convert_to_bcd(hour);
+ m_intreg[reg_minutes] = convert_to_bcd(minute);
+ m_intreg[reg_seconds] = convert_to_bcd(second);
+ m_intreg[reg_year] = convert_to_bcd(year);
+ m_intreg[reg_month] = convert_to_bcd(month);
+ m_intreg[reg_date] = convert_to_bcd(day);
+ m_intreg[reg_days] = convert_to_bcd(day_of_week);
+}
+
bool bq48x2_device::increment_bcd(uint8_t& bcdnumber, uint8_t limit, uint8_t min)
{
if (!valid_bcd(bcdnumber, min, limit))
@@ -114,6 +127,7 @@ bool bq48x2_device::increment_bcd(uint8_t& bcdnumber, uint8_t limit, uint8_t min
return false;
}
+// TODO: Remove; the real clock cannot verify BCD numbers.
bool bq48x2_device::valid_bcd(uint8_t value, uint8_t min, uint8_t max)
{
bool valid = ((value>=min) && (value<=max) && ((value&0x0f)<=9));
@@ -121,11 +135,6 @@ bool bq48x2_device::valid_bcd(uint8_t value, uint8_t min, uint8_t max)
return valid;
}
-uint8_t bq48x2_device::to_bcd(uint8_t value)
-{
- return (((value / 10) << 4) & 0xf0) | (value % 10);
-}
-
// ----------------------------------------------------
/*
@@ -134,13 +143,6 @@ uint8_t bq48x2_device::to_bcd(uint8_t value)
*/
TIMER_CALLBACK_MEMBER(bq48x2_device::rtc_clock_cb)
{
- // BCD-encoded numbers
- static const int days_in_month_table[12] =
- {
- 0x31,0x28,0x31, 0x30,0x31,0x30,
- 0x31, 0x31, 0x30, 0x31, 0x30, 0x31
- };
-
// Just for debugging
static const char* dow[7] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
@@ -152,6 +154,7 @@ TIMER_CALLBACK_MEMBER(bq48x2_device::rtc_clock_cb)
return;
// When the timer ticks, the 100ths are 0.
+ // TODO: Verify this with a real chip
m_intreg[reg_100ths] = 0;
if (carry)
@@ -163,32 +166,18 @@ TIMER_CALLBACK_MEMBER(bq48x2_device::rtc_clock_cb)
carry = increment_bcd(m_intreg[reg_minutes], 0x59, 0);
if (carry)
- carry = increment_bcd(m_intreg[reg_hours], 0x23, 0);
-
- if (carry)
{
- uint8_t month = m_intreg[reg_month];
- uint8_t days = 30;
-
- if (valid_bcd(month, 0x01, 0x12))
- days = days_in_month_table[month-1];
-
- // Are leap years considered?
- #if DOLEAPYEARS
- if ((month==2)
- && ((m_intreg[reg_year]%4)==0)
- && ((m_intreg[reg_year]%100)!=0
- || (m_intreg[reg_year]%400)==0))
- days = 0x29;
- #endif
-
- increment_bcd(m_intreg[reg_days], 7, 1); // increment the day-of-week (no carry)
- carry = increment_bcd(m_intreg[reg_date], days, 1); // and now the day
+ increment_bcd(m_intreg[reg_hours], 0xff, 0);
+ if (m_intreg[reg_hours] == 0x24)
+ {
+ m_intreg[reg_hours] = 0;
+ carry = true;
+ }
}
if (carry)
- carry = increment_bcd(m_intreg[reg_month], 0x12, 1);
- if (carry)
- carry = increment_bcd(m_intreg[reg_year], 0x99, 0);
+ {
+ advance_days_bcd();
+ }
LOGMASKED(LOG_CLOCK, "%s 20%02x-%02x-%02x %02x:%02x:%02x\n",
dow[m_intreg[reg_days]-1], m_intreg[reg_year], m_intreg[reg_month], m_intreg[reg_date],
@@ -213,6 +202,40 @@ TIMER_CALLBACK_MEMBER(bq48x2_device::rtc_clock_cb)
}
}
}
+void bq48x2_device::advance_days_bcd()
+{
+ bool carry = false;
+
+ // BCD-encoded numbers
+ static const int days_in_month_table[12] =
+ {
+ 0x31, 0x28, 0x31, 0x30, 0x31, 0x30,
+ 0x31, 0x31, 0x30, 0x31, 0x30, 0x31
+ };
+
+ uint8_t month = bcd_to_integer(m_intreg[reg_month]);
+ if (month > 12) month = 12;
+
+ // if (!valid_bcd(month, 0x01, 0x12)) month = 1;
+ uint8_t days = days_in_month_table[month-1];
+
+ // Leap years are indeed handled (but the year is only 2-digit)
+ if ((month==2) && ((m_intreg[reg_year]%4)==0))
+ days = 0x29;
+
+ increment_bcd(m_intreg[reg_days], 7, 1); // Increment the day-of-week (without carry)
+ carry = increment_bcd(m_intreg[reg_date], days, 1);
+
+ if (carry)
+ {
+ increment_bcd(m_intreg[reg_month], 0xff, 1);
+ if (m_intreg[reg_month] == 0x13)
+ {
+ m_intreg[reg_month] = 0x01;
+ increment_bcd(m_intreg[reg_year], 0xff, 0);
+ }
+ }
+}
uint8_t bq48x2_device::get_register(int number, uint8_t mask)
{
@@ -251,6 +274,7 @@ void bq48x2_device::transfer_to_int()
m_intreg[i] = get_register(i, regmask[i]);
// If we set the 100ths not to be 0, the next second will occur earlier
+ // TODO: Check this with the real chip
if (hds != m_intreg[reg_100ths])
m_clock_timer->adjust(attotime::from_msec(get_delay()), 0, attotime::from_seconds(1));
}
@@ -475,21 +499,6 @@ void bq48x2_device::connect_osc(bool conn)
}
}
-void bq48x2_device::get_system_time()
-{
- // Set time from system time
- system_time systime;
- machine().current_datetime(systime);
- m_intreg[reg_hours] = to_bcd(systime.local_time.hour);
- m_intreg[reg_minutes] = to_bcd(systime.local_time.minute);
- m_intreg[reg_seconds] = to_bcd(systime.local_time.second);
- m_intreg[reg_year] = to_bcd(systime.local_time.year%100);
- m_intreg[reg_month] = to_bcd(systime.local_time.month+1);
- m_intreg[reg_date] = to_bcd(systime.local_time.mday);
- m_intreg[reg_days] = to_bcd(systime.local_time.weekday+1);
- m_intreg[reg_100ths] = 0;
-}
-
int bq48x2_device::get_delay()
{
int hds = ((m_intreg[reg_100ths] & 0xf0)>>16) * 10 + (m_intreg[reg_100ths] & 0x0f);
@@ -522,7 +531,6 @@ void bq48x2_device::device_start()
save_pointer(NAME(m_intreg), 8);
// Start clock
- get_system_time();
connect_osc(true);
}
@@ -537,7 +545,6 @@ void bq48x2_device::nvram_read(emu_file &file)
{
file.read(m_sram.get(), m_memsize);
- get_system_time();
transfer_to_access(); // Transfer the system time into the readable registers
// Clear the saved flags
diff --git a/src/devices/machine/bq48x2.h b/src/devices/machine/bq48x2.h
index 359cca282b6..ddf4505b44f 100644
--- a/src/devices/machine/bq48x2.h
+++ b/src/devices/machine/bq48x2.h
@@ -13,9 +13,13 @@
#pragma once
+#include "dirtc.h"
+
// ======================> bq48x2_device
-class bq48x2_device : public device_t, public device_nvram_interface
+class bq48x2_device : public device_t,
+ public device_nvram_interface,
+ public device_rtc_interface
{
public:
auto interrupt_cb() { return m_interrupt_cb.bind(); }
@@ -60,12 +64,15 @@ protected:
void set_watchdog_timer();
private:
+ // Inherited from device_rtc_interface
+ void rtc_clock_updated(int year, int month, int day, int day_of_week, int hour, int minute, int second) override;
+ bool rtc_feature_y2k() const override { return false; }
+ bool rtc_feature_leap_year() const override { return true; }
+ bool rtc_battery_backed() const override { return true; }
+
// Sanity-check BCD number
bool valid_bcd(uint8_t value, uint8_t min, uint8_t max);
- // Convert to BCD
- uint8_t to_bcd(uint8_t value);
-
// Increment BCD number
bool increment_bcd(uint8_t& bcdnumber, uint8_t limit, uint8_t min);
@@ -84,6 +91,9 @@ private:
// Check bits in register
bool is_set(int number, uint8_t flag);
+ // Advance
+ void advance_days_bcd();
+
// Copy register contents from the internal registers to SRAM or back
void transfer_to_int();
void transfer_to_access();
@@ -100,9 +110,6 @@ private:
// Set timers
void set_periodic_timer();
- // Get time from system
- void get_system_time();
-
// Get the delay until the next second
int get_delay();