diff options
Diffstat (limited to 'src/mame/audio/namco52.cpp')
-rw-r--r-- | src/mame/audio/namco52.cpp | 12 |
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); } |