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// license:BSD-3-Clause
// copyright-holders:smf
#include "emu.h"
#include "clock.h"
DEFINE_DEVICE_TYPE(CLOCK, clock_device, "clock", "Clock")
clock_device::clock_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: device_t(mconfig, CLOCK, tag, owner, clock),
m_signal(0),
m_timer(nullptr),
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 == nullptr)
{
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 != nullptr)
{
m_timer->adjust(attotime::never);
}
}
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