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Diffstat (limited to 'src/devices/machine/upd4991a.cpp')
-rw-r--r-- | src/devices/machine/upd4991a.cpp | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/src/devices/machine/upd4991a.cpp b/src/devices/machine/upd4991a.cpp new file mode 100644 index 00000000000..c58fcfef159 --- /dev/null +++ b/src/devices/machine/upd4991a.cpp @@ -0,0 +1,135 @@ +// license:BSD-3-Clause +// copyright-holders: Angelo Salese +/************************************************************************************************** + + NEC uPD4991/uPD4991a parallel RTC + + uPD4991 should be very similar but with "30% more power consumption" (cit.) + + TODO: + - bare minimum to make PC98HA happy; + - set clock regs; + - alarm & timer pulse; + - AM/PM hour mode; + - leap year; + - busy flag; + - adjust/clock stop/clock wait mechanisms; + +**************************************************************************************************/ + +#include "emu.h" +#include "upd4991a.h" + + +//************************************************************************************************* +// GLOBAL VARIABLES +//************************************************************************************************* + +// device type definition +DEFINE_DEVICE_TYPE(UPD4991A, upd4991a_device, "upd4991a", "NEC uPD4991a parallel RTC") + + +//************************************************************************************************* +// LIVE DEVICE +//************************************************************************************************* + +//------------------------------------------------- +// upd4991a_device - constructor +//------------------------------------------------- + +upd4991a_device::upd4991a_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) + : device_t(mconfig, UPD4991A, tag, owner, clock) + , device_rtc_interface(mconfig, *this) + , m_timer_clock(nullptr) +{ + std::fill(std::begin(m_rtc_regs), std::end(m_rtc_regs), 0); +} + + +//------------------------------------------------- +// device_validity_check - perform validity checks +// on this device +//------------------------------------------------- + +void upd4991a_device::device_validity_check(validity_checker &valid) const +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void upd4991a_device::device_start() +{ + m_timer_clock = timer_alloc(FUNC(upd4991a_device::clock_tick), this); + m_timer_clock->adjust(attotime::from_hz(clock() / 32768), 0, attotime::from_hz(clock() / 32768)); + + save_item(NAME(m_address)); +} + + +TIMER_CALLBACK_MEMBER(upd4991a_device::clock_tick) +{ + advance_seconds(); +} + +//------------------------------------------------- +// rtc_clock_updated - +//------------------------------------------------- + +void upd4991a_device::rtc_clock_updated(int year, int month, int day, int day_of_week, int hour, int minute, int second) +{ +/* +[0-1] +xxxx xxxx seconds +[2-3] +xxxx xxxx minutes +[4-5] +xxxx xxxx hour +[6-7] +---- xxxx date digit (weekday?) +xxxx ---- 1 day digit +[8-9] +---- xxxx 10 day digit +xxxx ---- 1 month digit +[a-b] +---- xxxx 10 month digit +xxxx ---- 1 year digit +[c-d] +---- xxxx 10 year digit +xxxx ---- control register 1 (write only) +[e-f] +---- xxxx control register 2 (read/write) +xxxx ---- mode register (write only) +*/ + m_rtc_regs[0] = convert_to_bcd(second); + m_rtc_regs[1] = convert_to_bcd(minute); + m_rtc_regs[2] = convert_to_bcd(hour); + const u8 bcd_day = convert_to_bcd(day); + const u8 bcd_month = convert_to_bcd(month); + const u8 bcd_year = convert_to_bcd(year); + m_rtc_regs[3] = (day_of_week-1) | ((bcd_day & 0x0f) << 4); + m_rtc_regs[4] = ((bcd_day & 0xf0) >> 4) | ((bcd_month & 0x0f) << 4); + m_rtc_regs[5] = ((bcd_month & 0xf0) >> 4) | ((bcd_year & 0x0f) << 4); + m_rtc_regs[6] = ((bcd_year & 0xf0) >> 4); +} + +//************************************************************************************************* +// READ/WRITE HANDLERS +//************************************************************************************************* + +u8 upd4991a_device::data_r(offs_t offset) +{ + return m_rtc_regs[m_address >> 1] >> ((m_address & 1) ? 4 : 0); +} + +void upd4991a_device::data_w(offs_t offset, u8 data) +{ + // ... +} + +void upd4991a_device::address_w(offs_t offset, u8 data) +{ + m_address = data & 0xf; +} |