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hd63450: speed up max rate transfers

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This commit is contained in:
cracyc 2021-05-29 14:11:27 -05:00
parent b2c8477b23
commit 1cc4958ada
1 changed files with 4 additions and 3 deletions
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7
src/devices/machine/hd63450.cpp
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@ -298,7 +298,8 @@ void hd63450_device::dma_transfer_start(int channel)
}
// Burst transfers will halt the CPU until the transfer is complete
if ((m_reg[channel].dcr & 0xc0) == 0x00) // Burst transfer
// max rate transfer hold the bus
if (((m_reg[channel].dcr & 0xc0) == 0x00) || ((m_reg[channel].ocr & 3) == 1)) // Burst transfer
{
m_cpu->set_input_line(INPUT_LINE_HALT, ASSERT_LINE);
m_timer[channel]->adjust(attotime::zero, channel, m_burst_clock[channel]);
@ -494,8 +495,8 @@ void hd63450_device::single_transfer(int x)
m_reg[x].csr &= ~0x08; // channel no longer active
m_reg[x].ccr &= ~0xc0;
// Burst transfer
if ((m_reg[x].dcr & 0xc0) == 0x00)
// Burst transfer or max rate transfer
if (((m_reg[x].dcr & 0xc0) == 0x00) || ((m_reg[x].ocr & 3) == 1))
{
m_cpu->set_input_line(INPUT_LINE_HALT, CLEAR_LINE);
}