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Diffstat (limited to 'src/mame/audio/namco52.cpp')
-rw-r--r--src/mame/audio/namco52.cpp12
1 files changed, 2 insertions, 10 deletions
diff --git a/src/mame/audio/namco52.cpp b/src/mame/audio/namco52.cpp
index 504a093afa7..0b960a69604 100644
--- a/src/mame/audio/namco52.cpp
+++ b/src/mame/audio/namco52.cpp
@@ -114,17 +114,9 @@ void namco_52xx_device::write(uint8_t data)
{
machine().scheduler().synchronize(timer_expired_delegate(FUNC(namco_52xx_device::latch_callback),this), data);
+ // TODO: should use chip_select line for this
m_cpu->set_input_line(0, ASSERT_LINE);
-
- // The execution time of one instruction is ~4us, so we must make sure to
- // give the cpu time to poll the /IRQ input before we clear it.
- // The input clock to the 06XX interface chip is 64H, that is
- // 18432000/6/64 = 48kHz, so it makes sense for the irq line to be
- // asserted for one clock cycle ~= 21us.
-
- /* the 52xx uses TSTI to check for an interrupt; it also may be handling
- a timer interrupt, so we need to ensure the IRQ line is held long enough */
- machine().scheduler().timer_set(attotime::from_usec(5*21), timer_expired_delegate(FUNC(namco_52xx_device::irq_clear),this), 0);
+ machine().scheduler().timer_set(attotime::from_usec(100), timer_expired_delegate(FUNC(namco_52xx_device::irq_clear),this), 0);
}