diff options
Diffstat (limited to 'src/devices/machine/clock.c')
-rw-r--r-- | src/devices/machine/clock.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/src/devices/machine/clock.c b/src/devices/machine/clock.c new file mode 100644 index 00000000000..9896bebabcc --- /dev/null +++ b/src/devices/machine/clock.c @@ -0,0 +1,68 @@ +// license:BSD-3-Clause +// copyright-holders:smf +#include "clock.h" + +const device_type CLOCK = &device_creator<clock_device>; + +clock_device::clock_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : device_t(mconfig, CLOCK, "Clock", tag, owner, clock, "clock", __FILE__), + m_signal(0), + m_timer(NULL), + m_signal_handler(*this) +{ +} + +void clock_device::device_start() +{ + m_signal_handler.resolve(); + + save_item(NAME(m_signal)); +} + +void clock_device::device_clock_changed() +{ + update_timer(); +} + +attotime clock_device::period() +{ + if (m_clock > 0) + return attotime::from_hz(m_clock * 2); + + return attotime::never; +} + +void clock_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) +{ + m_signal = !m_signal; + m_signal_handler(m_signal); + + m_timer->adjust(period()); +} + +void clock_device::update_timer() +{ + if (!m_signal_handler.isnull() && m_clock > 0) + { + if (m_timer == NULL) + { + m_timer = timer_alloc(0); + m_timer->adjust(period()); + } + else + { + attotime next = period() - m_timer->elapsed(); + + if (next < attotime::zero) + { + next = attotime::zero; + } + + m_timer->adjust(next); + } + } + else if (m_timer != NULL) + { + m_timer->adjust(attotime::never); + } +} |