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-rw-r--r--src/devices/machine/clock.cpp140
1 files changed, 120 insertions, 20 deletions
diff --git a/src/devices/machine/clock.cpp b/src/devices/machine/clock.cpp
index 374dc8a16a8..803e3d3a55f 100644
--- a/src/devices/machine/clock.cpp
+++ b/src/devices/machine/clock.cpp
@@ -1,46 +1,146 @@
// license:BSD-3-Clause
-// copyright-holders:smf
+// copyright-holders:smf, hap
+/*
+
+Generic clock signal device
+
+Set the period either with device_t m_clock, or with set_period if it needs
+to be more fine-tuned (m_clock has higher priority).
+
+The duty cycle can be changed with set_duty_cycle (default is 50%), or the
+pulse width (active time) can be set directly with set_pulse_width.
+
+Output signal at machine start is right after falling edge.
+
+TODO:
+- add one-shot trigger? eg. monostable 555
+
+*/
+
#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),
+clock_device::clock_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) :
+ device_t(mconfig, CLOCK, tag, owner, clock),
m_signal(0),
- m_timer(nullptr),
+ m_output(-1),
+ m_duty(0.5),
+ m_period(attotime::never),
+ m_pw(attotime::never),
+ m_timer_init(nullptr),
+ m_timer_tick(nullptr),
m_signal_handler(*this)
{
}
void clock_device::device_start()
{
- m_signal_handler.resolve();
+ m_signal_handler.resolve_safe();
save_item(NAME(m_signal));
+ save_item(NAME(m_output));
+ save_item(NAME(m_duty));
+ save_item(NAME(m_period));
+ save_item(NAME(m_pw));
+ save_item(NAME(m_thigh));
+ save_item(NAME(m_tlow));
+
+ m_timer_init = timer_alloc(TID_CLOCK_INIT);
+ m_timer_tick = timer_alloc(TID_CLOCK_TICK);
+ reinit();
}
-void clock_device::device_clock_changed()
+void clock_device::reinit()
{
- if (!m_signal_handler.isnull() && m_clock > 0)
- {
- if (m_timer == nullptr)
- m_timer = timer_alloc(0);
+ if (!m_timer_init)
+ return;
- const attotime period(attotime::from_hz(m_clock * 2));
-
- attotime next = period - m_timer->elapsed();
- if (next < attotime::zero)
- next = attotime::zero;
+ // not using synchronize(), that may retrigger more than once
+ m_timer_init->adjust(attotime::zero);
+}
- m_timer->adjust(next, 0, period);
+void clock_device::output()
+{
+ if (m_signal != m_output)
+ {
+ m_output = m_signal;
+ m_signal_handler(m_output);
}
- else if (m_timer != nullptr)
- m_timer->adjust(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);
+ switch (id)
+ {
+ case TID_CLOCK_INIT:
+ {
+ attotime period = (m_clock > 0) ? attotime::from_hz(m_clock) : m_period;
+ assert(!period.is_zero());
+
+ if (period.is_never())
+ {
+ m_timer_tick->adjust(attotime::never);
+ return;
+ }
+
+ if (!m_pw.is_never())
+ {
+ // set timing via pulse width
+ attotime pw = m_pw;
+ if (pw > period)
+ pw = period;
+
+ m_thigh = pw;
+ m_tlow = period - pw;
+ }
+ else
+ {
+ // set timing via duty cycle
+ if (m_duty == 0.5)
+ {
+ m_thigh = period / 2;
+ m_tlow = m_thigh;
+ }
+ else if (m_duty == 0.0)
+ {
+ m_thigh = attotime::zero;
+ m_tlow = period;
+ }
+ else if (m_duty == 1.0)
+ {
+ m_thigh = period;
+ m_tlow = attotime::zero;
+ }
+ else
+ {
+ double p = period.as_double();
+ m_thigh = attotime::from_double(m_duty * p);
+ m_tlow = attotime::from_double((1.0 - m_duty) * p);
+ }
+ }
+
+ attotime next = m_signal ? m_thigh : m_tlow;
+ if (next < m_timer_tick->remaining())
+ m_timer_tick->adjust(next);
+
+ break;
+ }
+
+ case TID_CLOCK_TICK:
+ if (m_thigh.is_zero())
+ m_signal = 0;
+ else if (m_tlow.is_zero())
+ m_signal = 1;
+ else
+ m_signal ^= 1;
+
+ m_timer_tick->adjust(m_signal ? m_thigh : m_tlow);
+ output();
+ break;
+
+ default:
+ break;
+ }
}