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cs4031: Set DMA controller clocks via chipset configuration

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This commit is contained in:
Dirk Best 2013-06-14 11:45:49 +00:00
parent 9fd839af51
commit 47b4063fb8
2 changed files with 41 additions and 8 deletions
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47
src/mess/machine/cs4031.c
View File

@ -82,6 +82,11 @@ const char* cs4031_device::m_register_names[] =
/* 1f */ "RESERVED"
};
const float cs4031_device::m_dma_clock_divider[] =
{
10, 8, 6, 0, 0, 0, 0, 0, 5, 4, 3, 2.5, 2, 1.5, 0, 0
};
//-------------------------------------------------
// machine_config_additions - device-specific
// machine configurations
@ -159,8 +164,8 @@ const struct pit8253_interface cs4031_pit_config =
};
static MACHINE_CONFIG_FRAGMENT( cs4031 )
MCFG_I8237_ADD("dma1", XTAL_14_31818MHz/3 /* todo: set to 0, instead set via config register */, dma1_config)
MCFG_I8237_ADD("dma2", XTAL_14_31818MHz/3 /* todo: set to 0, instead set via config register */, dma2_config)
MCFG_I8237_ADD("dma1", 0, dma1_config)
MCFG_I8237_ADD("dma2", 0, dma2_config)
MCFG_PIC8259_ADD("intc1", WRITELINE(cs4031_device, intc1_int_w), VCC, READ8(cs4031_device, intc1_slave_ack_r))
MCFG_PIC8259_ADD("intc2", DEVWRITELINE("intc1", pic8259_device, ir2_w), GND, NULL)
MCFG_PIT8254_ADD("ctc", cs4031_pit_config)
@ -330,6 +335,8 @@ void cs4031_device::device_reset()
update_read_regions();
update_write_regions();
// initialize dma controller clocks
update_dma_clock();
}
//-------------------------------------------------
@ -430,6 +437,22 @@ void cs4031_device::set_dma_channel(int channel, bool state)
}
}
void cs4031_device::update_dma_clock()
{
if (m_dma_clock_divider[m_registers[DMA_CLOCK] & 0x0f] != 0)
{
UINT32 dma_clock = clock() / m_dma_clock_divider[m_registers[DMA_CLOCK] & 0x0f];
if (!BIT(m_registers[DMA_WAIT_STATE], 0))
dma_clock /= 2;
logerror("cs4031_device::update_dma_clock: dma clock is now %u\n", dma_clock);
m_dma1->set_unscaled_clock(dma_clock);
m_dma2->set_unscaled_clock(dma_clock);
}
}
//**************************************************************************
// INTERRUPTS
@ -539,13 +562,20 @@ WRITE8_MEMBER( cs4031_device::config_data_w )
// execute command
switch (m_address)
{
case 0x01: break;
case DMA_WAIT_STATE:
update_dma_clock();
break;
case 0x05: break;
case 0x06: break;
case 0x07: break;
case 0x08: break;
case 0x09: break;
case 0x0a: break;
case DMA_CLOCK:
update_dma_clock();
break;
case 0x10: break;
case 0x11: break;
case 0x12: break;
@ -556,20 +586,21 @@ WRITE8_MEMBER( cs4031_device::config_data_w )
case 0x17: break;
case 0x18: break;
case 0x19:
case SHADOW_READ:
update_read_regions();
break;
case 0x1a:
case SHADOW_WRITE:
update_write_regions();
break;
case 0x1b:
case ROMCS:
update_read_regions();
update_write_regions();
break;
case 0x1c: break;
case SOFT_RESET_AND_GATEA20:
break;
}
}

2
src/mess/machine/cs4031.h
View File

@ -201,6 +201,7 @@ private:
offs_t page_offset();
void set_dma_channel(int channel, bool state);
void update_dma_clock();
void nmi();
void a20m();
@ -248,6 +249,7 @@ private:
// chipset configuration
static const char* m_register_names[];
static const float m_dma_clock_divider[];
enum
{