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/***************************************************************************
machine.c
Functions to emulate general aspects of the machine (RAM, ROM, interrupts,
I/O ports)
***************************************************************************/
#include "driver.h"
#include "includes/bigevglf.h"
READ8_HANDLER( bigevglf_68705_port_a_r )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
return (state->port_a_out & state->ddr_a) | (state->port_a_in & ~state->ddr_a);
}
WRITE8_HANDLER( bigevglf_68705_port_a_w )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
state->port_a_out = data;
}
WRITE8_HANDLER( bigevglf_68705_ddr_a_w )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
state->ddr_a = data;
}
READ8_HANDLER( bigevglf_68705_port_b_r )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
return (state->port_b_out & state->ddr_b) | (state->port_b_in & ~state->ddr_b);
}
WRITE8_HANDLER( bigevglf_68705_port_b_w )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
if ((state->ddr_b & 0x02) && (~state->port_b_out & 0x02) && (data & 0x02)) /* positive going transition of the clock */
{
cpu_set_input_line(state->mcu, 0, CLEAR_LINE);
state->main_sent = 0;
}
if ((state->ddr_b & 0x04) && (~state->port_b_out & 0x04) && (data & 0x04) ) /* positive going transition of the clock */
{
state->from_mcu = state->port_a_out;
state->mcu_sent = 0;
}
state->port_b_out = data;
}
WRITE8_HANDLER( bigevglf_68705_ddr_b_w )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
state->ddr_b = data;
}
READ8_HANDLER( bigevglf_68705_port_c_r )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
state->port_c_in = 0;
if (state->main_sent)
state->port_c_in |= 0x01;
if (state->mcu_sent)
state->port_c_in |= 0x02;
return (state->port_c_out & state->ddr_c) | (state->port_c_in & ~state->ddr_c);
}
WRITE8_HANDLER( bigevglf_68705_port_c_w )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
state->port_c_out = data;
}
WRITE8_HANDLER( bigevglf_68705_ddr_c_w )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
state->ddr_c = data;
}
WRITE8_HANDLER( bigevglf_mcu_w )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
state->port_a_in = data;
state->main_sent = 1;
cpu_set_input_line(state->mcu, 0, ASSERT_LINE);
}
READ8_HANDLER( bigevglf_mcu_r )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
state->mcu_sent = 1;
return state->from_mcu;
}
READ8_HANDLER( bigevglf_mcu_status_r )
{
bigevglf_state *state = (bigevglf_state *)space->machine->driver_data;
int res = 0;
if (!state->main_sent)
res |= 0x08;
if (!state->mcu_sent)
res |= 0x10;
return res;
}
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