diff options
Diffstat (limited to 'src/devices/machine/6522via.c')
-rw-r--r-- | src/devices/machine/6522via.c | 985 |
1 files changed, 985 insertions, 0 deletions
diff --git a/src/devices/machine/6522via.c b/src/devices/machine/6522via.c new file mode 100644 index 00000000000..56a35e19040 --- /dev/null +++ b/src/devices/machine/6522via.c @@ -0,0 +1,985 @@ +// license:BSD-3-Clause +// copyright-holders:Peter Trauner, Mathis Rosenhauer +/********************************************************************** + + Rockwell 6522 VIA interface and emulation + + This function emulates the functionality of up to 8 6522 + versatile interface adapters. + + This is based on the M6821 emulation in MAME. + + To do: + + T2 pulse counting mode + Pulse mode handshake output + More shift register + +**********************************************************************/ + +/* + 1999-Dec-22 PeT + vc20 random number generation only partly working + (reads (uninitialized) timer 1 and timer 2 counter) + timer init, reset, read changed + */ + +#include "emu.h" +#include "6522via.h" + +/*************************************************************************** + PARAMETERS +***************************************************************************/ + +#define TRACE_VIA 0 + + +/*************************************************************************** + MACROS +***************************************************************************/ + +/* Macros for PCR */ +#define CA1_LOW_TO_HIGH(c) (c & 0x01) +#define CA1_HIGH_TO_LOW(c) (!(c & 0x01)) + +#define CB1_LOW_TO_HIGH(c) (c & 0x10) +#define CB1_HIGH_TO_LOW(c) (!(c & 0x10)) + +#define CA2_INPUT(c) (!(c & 0x08)) +#define CA2_LOW_TO_HIGH(c) ((c & 0x0c) == 0x04) +#define CA2_HIGH_TO_LOW(c) ((c & 0x0c) == 0x00) +#define CA2_IND_IRQ(c) ((c & 0x0a) == 0x02) + +#define CA2_OUTPUT(c) (c & 0x08) +#define CA2_AUTO_HS(c) ((c & 0x0c) == 0x08) +#define CA2_HS_OUTPUT(c) ((c & 0x0e) == 0x08) +#define CA2_PULSE_OUTPUT(c) ((c & 0x0e) == 0x0a) +#define CA2_FIX_OUTPUT(c) ((c & 0x0c) == 0x0c) +#define CA2_OUTPUT_LEVEL(c) ((c & 0x02) >> 1) + +#define CB2_INPUT(c) (!(c & 0x80)) +#define CB2_LOW_TO_HIGH(c) ((c & 0xc0) == 0x40) +#define CB2_HIGH_TO_LOW(c) ((c & 0xc0) == 0x00) +#define CB2_IND_IRQ(c) ((c & 0xa0) == 0x20) + +#define CB2_OUTPUT(c) (c & 0x80) +#define CB2_AUTO_HS(c) ((c & 0xc0) == 0x80) +#define CB2_HS_OUTPUT(c) ((c & 0xe0) == 0x80) +#define CB2_PULSE_OUTPUT(c) ((c & 0xe0) == 0xa0) +#define CB2_FIX_OUTPUT(c) ((c & 0xc0) == 0xc0) +#define CB2_OUTPUT_LEVEL(c) ((c & 0x20) >> 5) + +/* Macros for ACR */ +#define PA_LATCH_ENABLE(c) (c & 0x01) +#define PB_LATCH_ENABLE(c) (c & 0x02) + +#define SR_DISABLED(c) (!(c & 0x1c)) +#define SI_T2_CONTROL(c) ((c & 0x1c) == 0x04) +#define SI_O2_CONTROL(c) ((c & 0x1c) == 0x08) +#define SI_EXT_CONTROL(c) ((c & 0x1c) == 0x0c) +#define SO_T2_RATE(c) ((c & 0x1c) == 0x10) +#define SO_T2_CONTROL(c) ((c & 0x1c) == 0x14) +#define SO_O2_CONTROL(c) ((c & 0x1c) == 0x18) +#define SO_EXT_CONTROL(c) ((c & 0x1c) == 0x1c) + +#define T1_SET_PB7(c) (c & 0x80) +#define T1_CONTINUOUS(c) (c & 0x40) +#define T2_COUNT_PB6(c) (c & 0x20) + +/* Interrupt flags */ +#define INT_CA2 0x01 +#define INT_CA1 0x02 +#define INT_SR 0x04 +#define INT_CB2 0x08 +#define INT_CB1 0x10 +#define INT_T2 0x20 +#define INT_T1 0x40 +#define INT_ANY 0x80 + +#define CLR_PA_INT() clear_int(INT_CA1 | ((!CA2_IND_IRQ(m_pcr)) ? INT_CA2: 0)) +#define CLR_PB_INT() clear_int(INT_CB1 | ((!CB2_IND_IRQ(m_pcr)) ? INT_CB2: 0)) + +#define IFR_DELAY 3 + +#define TIMER1_VALUE (m_t1ll+(m_t1lh<<8)) +#define TIMER2_VALUE (m_t2ll+(m_t2lh<<8)) + + + +/*************************************************************************** + INLINE FUNCTIONS +***************************************************************************/ + +UINT16 via6522_device::get_counter1_value() +{ + UINT16 val; + + if(m_t1_active) + { + val = attotime_to_clocks(m_t1->remaining()) - IFR_DELAY; + } + else + { + val = 0xffff - attotime_to_clocks(machine().time() - m_time1); + } + + return val; +} + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +// device type definition +const device_type VIA6522 = &device_creator<via6522_device>; + +DEVICE_ADDRESS_MAP_START( map, 8, via6522_device ) + AM_RANGE(0x00, 0x0f) AM_READWRITE(read, write) +ADDRESS_MAP_END + +//------------------------------------------------- +// via6522_device - constructor +//------------------------------------------------- + +via6522_device::via6522_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : device_t(mconfig, VIA6522, "6522 VIA", tag, owner, clock, "via6522", __FILE__), + m_in_a_handler(*this), + m_in_b_handler(*this), + m_out_a_handler(*this), + m_out_b_handler(*this), + m_ca2_handler(*this), + m_cb1_handler(*this), + m_cb2_handler(*this), + m_irq_handler(*this), + m_in_a(0xff), + m_in_ca1(0), + m_in_ca2(0), + m_out_ca2(0), + m_in_b(0), + m_in_cb1(0), + m_in_cb2(0), + m_pcr(0), + m_acr(0), + m_ier(0), + m_ifr(0) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void via6522_device::device_start() +{ + m_in_a_handler.resolve(); + m_in_b_handler.resolve(); + m_out_a_handler.resolve_safe(); + m_out_b_handler.resolve_safe(); + m_cb1_handler.resolve_safe(); + m_ca2_handler.resolve_safe(); + m_cb2_handler.resolve_safe(); + m_irq_handler.resolve_safe(); + + m_t1ll = 0xf3; /* via at 0x9110 in vic20 show these values */ + m_t1lh = 0xb5; /* ports are not written by kernel! */ + m_t2ll = 0xff; /* taken from vice */ + m_t2lh = 0xff; + m_sr = 0; + + m_time2 = m_time1 = machine().time(); + m_t1 = timer_alloc(TIMER_T1); + m_t2 = timer_alloc(TIMER_T2); + m_ca2_timer = timer_alloc(TIMER_CA2); + m_shift_timer = timer_alloc(TIMER_SHIFT); + + /* Default clock is from CPU1 */ + if (clock() == 0) + { + set_unscaled_clock(machine().firstcpu->clock()); + } + + /* save state register */ + save_item(NAME(m_in_a)); + save_item(NAME(m_in_ca1)); + save_item(NAME(m_in_ca2)); + save_item(NAME(m_out_a)); + save_item(NAME(m_out_ca2)); + save_item(NAME(m_ddr_a)); + save_item(NAME(m_latch_a)); + save_item(NAME(m_in_b)); + save_item(NAME(m_in_cb1)); + save_item(NAME(m_in_cb2)); + save_item(NAME(m_out_b)); + save_item(NAME(m_out_cb1)); + save_item(NAME(m_out_cb2)); + save_item(NAME(m_ddr_b)); + save_item(NAME(m_latch_b)); + save_item(NAME(m_t1cl)); + save_item(NAME(m_t1ch)); + save_item(NAME(m_t1ll)); + save_item(NAME(m_t1lh)); + save_item(NAME(m_t2cl)); + save_item(NAME(m_t2ch)); + save_item(NAME(m_t2ll)); + save_item(NAME(m_t2lh)); + save_item(NAME(m_sr)); + save_item(NAME(m_pcr)); + save_item(NAME(m_acr)); + save_item(NAME(m_ier)); + save_item(NAME(m_ifr)); + save_item(NAME(m_time1)); + save_item(NAME(m_t1_active)); + save_item(NAME(m_t1_pb7)); + save_item(NAME(m_time2)); + save_item(NAME(m_t2_active)); + save_item(NAME(m_shift_counter)); +} + + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void via6522_device::device_reset() +{ + m_out_a = 0; + m_out_ca2 = 1; + m_ddr_a = 0; + m_latch_a = 0; + + m_out_b = 0; + m_out_cb1 = 1; + m_out_cb2 = 1; + m_ddr_b = 0; + m_latch_b = 0; + + m_t1cl = 0; + m_t1ch = 0; + m_t2cl = 0; + m_t2ch = 0; + + m_pcr = 0; + m_acr = 0; + m_ier = 0; + m_ifr = 0; + m_t1_active = 0; + m_t1_pb7 = 1; + m_t2_active = 0; + m_shift_counter = 0; + + output_pa(); + output_pb(); + m_ca2_handler(m_out_ca2); + m_cb1_handler(m_out_cb1); + m_cb2_handler(m_out_cb2); +} + + +void via6522_device::output_irq() +{ + if (m_ier & m_ifr & 0x7f) + { + if ((m_ifr & INT_ANY) == 0) + { + m_ifr |= INT_ANY; + m_irq_handler(ASSERT_LINE); + } + } + else + { + if (m_ifr & INT_ANY) + { + m_ifr &= ~INT_ANY; + m_irq_handler(CLEAR_LINE); + } + } +} + + +/*------------------------------------------------- + via_set_int - external interrupt check +-------------------------------------------------*/ + +void via6522_device::set_int(int data) +{ + if (!(m_ifr & data)) + { + m_ifr |= data; + + output_irq(); + + if (TRACE_VIA) + { + logerror("%s:6522VIA chip %s: IFR = %02X\n", machine().describe_context(), tag(), m_ifr); + } + } +} + + +/*------------------------------------------------- + via_clear_int - external interrupt check +-------------------------------------------------*/ + +void via6522_device::clear_int(int data) +{ + if (m_ifr & data) + { + m_ifr &= ~data; + + output_irq(); + + if (TRACE_VIA) + { + logerror("%s:6522VIA chip %s: IFR = %02X\n", machine().describe_context(), tag(), m_ifr); + } + } +} + + +/*------------------------------------------------- + via_shift +-------------------------------------------------*/ + +void via6522_device::shift_out() +{ + m_out_cb2 = (m_sr >> 7) & 1; + m_sr = (m_sr << 1) | m_out_cb2; + + m_cb2_handler(m_out_cb2); + + if (!SO_T2_RATE(m_acr)) + { + m_shift_counter = (m_shift_counter + 1) % 8; + + if (m_shift_counter == 0) + { + set_int(INT_SR); + } + } +} + +void via6522_device::shift_in() +{ + m_sr = (m_sr << 1) | (m_in_cb2 & 1); + + m_shift_counter = (m_shift_counter + 1) % 8; + + if (m_shift_counter == 0) + { + set_int(INT_SR); + } +} + + +void via6522_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) +{ + switch (id) + { + case TIMER_SHIFT: + m_out_cb1 = 0; + m_cb1_handler(m_out_cb1); + + if (SO_T2_RATE(m_acr) || SO_T2_CONTROL(m_acr) || SO_O2_CONTROL(m_acr)) + { + shift_out(); + } + + m_out_cb1 = 1; + m_cb1_handler(m_out_cb1); + + if (SI_T2_CONTROL(m_acr) || SI_O2_CONTROL(m_acr)) + { + shift_in(); + } + + if (SO_T2_RATE(m_acr) || m_shift_counter) + { + if (SI_O2_CONTROL(m_acr) || SO_O2_CONTROL(m_acr)) + { + m_shift_timer->adjust(clocks_to_attotime(2)); + } + else + { + m_shift_timer->adjust(clocks_to_attotime((m_t2ll + 2)*2)); + } + } + break; + + case TIMER_T1: + if (T1_CONTINUOUS (m_acr)) + { + m_t1_pb7 = !m_t1_pb7; + m_t1->adjust(clocks_to_attotime(TIMER1_VALUE + IFR_DELAY)); + } + else + { + m_t1_pb7 = 1; + m_t1_active = 0; + m_time1 = machine().time(); + } + + if (T1_SET_PB7(m_acr)) + { + output_pb(); + } + + set_int(INT_T1); + break; + + case TIMER_T2: + m_t2_active = 0; + m_time2 = machine().time(); + + set_int(INT_T2); + break; + + case TIMER_CA2: + m_out_ca2 = 1; + m_ca2_handler(m_out_ca2); + break; + } +} + +UINT8 via6522_device::input_pa() +{ + /// TODO: REMOVE THIS + if (!m_in_a_handler.isnull()) + { + if (m_ddr_a != 0xff) + m_in_a = m_in_a_handler(0); + + return (m_out_a & m_ddr_a) + (m_in_a & ~m_ddr_a); + } + + return m_in_a & (m_out_a | ~m_ddr_a); +} + +void via6522_device::output_pa() +{ + UINT8 pa = (m_out_a & m_ddr_a) | ~m_ddr_a; + m_out_a_handler(pa); +} + +UINT8 via6522_device::input_pb() +{ + /// TODO: REMOVE THIS + if (m_ddr_b != 0xff && !m_in_b_handler.isnull()) + { + m_in_b = m_in_b_handler(0); + } + + UINT8 pb = (m_out_b & m_ddr_b) + (m_in_b & ~m_ddr_b); + + if (T1_SET_PB7(m_acr)) + pb = (pb & 0x7f) | (m_t1_pb7 << 7); + + return pb; +} + +void via6522_device::output_pb() +{ + UINT8 pb = (m_out_b & m_ddr_b) | ~m_ddr_b; + + if (T1_SET_PB7(m_acr)) + pb = (pb & 0x7f) | (m_t1_pb7 << 7); + + m_out_b_handler(pb); +} + +/*------------------------------------------------- + via_r - CPU interface for VIA read +-------------------------------------------------*/ + +READ8_MEMBER( via6522_device::read ) +{ + int val = 0; + if (space.debugger_access()) + return 0; + + offset &= 0xf; + + switch (offset) + { + case VIA_PB: + /* update the input */ + if (PB_LATCH_ENABLE(m_acr) == 0) + { + val = input_pb(); + } + else + { + val = m_latch_b; + } + + CLR_PB_INT(); + break; + + case VIA_PA: + /* update the input */ + if (PA_LATCH_ENABLE(m_acr) == 0) + { + val = input_pa(); + } + else + { + val = m_latch_a; + } + + CLR_PA_INT(); + + if (m_out_ca2 && (CA2_PULSE_OUTPUT(m_pcr) || CA2_AUTO_HS(m_pcr))) + { + m_out_ca2 = 0; + m_ca2_handler(m_out_ca2); + } + + if (CA2_PULSE_OUTPUT(m_pcr)) + m_ca2_timer->adjust(clocks_to_attotime(1)); + + break; + + case VIA_PANH: + /* update the input */ + if (PA_LATCH_ENABLE(m_acr) == 0) + { + val = input_pa(); + } + else + { + val = m_latch_a; + } + break; + + case VIA_DDRB: + val = m_ddr_b; + break; + + case VIA_DDRA: + val = m_ddr_a; + break; + + case VIA_T1CL: + clear_int(INT_T1); + val = get_counter1_value() & 0xFF; + break; + + case VIA_T1CH: + val = get_counter1_value() >> 8; + break; + + case VIA_T1LL: + val = m_t1ll; + break; + + case VIA_T1LH: + val = m_t1lh; + break; + + case VIA_T2CL: + clear_int(INT_T2); + if (m_t2_active) + { + val = attotime_to_clocks(m_t2->remaining()) & 0xff; + } + else + { + if (T2_COUNT_PB6(m_acr)) + { + val = m_t2cl; + } + else + { + val = (0x10000 - (attotime_to_clocks(machine().time() - m_time2) & 0xffff) - 1) & 0xff; + } + } + break; + + case VIA_T2CH: + if (m_t2_active) + { + val = attotime_to_clocks(m_t2->remaining()) >> 8; + } + else + { + if (T2_COUNT_PB6(m_acr)) + { + val = m_t2ch; + } + else + { + val = (0x10000 - (attotime_to_clocks(machine().time() - m_time2) & 0xffff) - 1) >> 8; + } + } + break; + + case VIA_SR: + val = m_sr; + m_shift_counter=0; + clear_int(INT_SR); + if (SI_O2_CONTROL(m_acr)) + { + m_shift_timer->adjust(clocks_to_attotime(2)); + } + if (SI_T2_CONTROL(m_acr)) + { + m_shift_timer->adjust(clocks_to_attotime((m_t2ll + 2)*2)); + } + break; + + case VIA_PCR: + val = m_pcr; + break; + + case VIA_ACR: + val = m_acr; + break; + + case VIA_IER: + val = m_ier | 0x80; + break; + + case VIA_IFR: + val = m_ifr; + break; + } + return val; +} + + +/*------------------------------------------------- + via_w - CPU interface for VIA write +-------------------------------------------------*/ + +WRITE8_MEMBER( via6522_device::write ) +{ + offset &=0x0f; + + switch (offset) + { + case VIA_PB: + m_out_b = data; + + if (m_ddr_b != 0) + { + output_pb(); + } + + CLR_PB_INT(); + + if (m_out_cb2 && CB2_AUTO_HS(m_pcr)) + { + m_out_cb2 = 0; + m_cb2_handler(m_out_cb2); + } + break; + + case VIA_PA: + m_out_a = data; + + if (m_ddr_a != 0) + { + output_pa(); + } + + CLR_PA_INT(); + + if (m_out_ca2 && (CA2_PULSE_OUTPUT(m_pcr) || CA2_AUTO_HS(m_pcr))) + { + m_out_ca2 = 0; + m_ca2_handler(m_out_ca2); + } + + if (CA2_PULSE_OUTPUT(m_pcr)) + m_ca2_timer->adjust(clocks_to_attotime(1)); + + break; + + case VIA_PANH: + m_out_a = data; + + if (m_ddr_a != 0) + { + output_pa(); + } + + break; + + case VIA_DDRB: + if ( data != m_ddr_b ) + { + m_ddr_b = data; + + output_pb(); + } + break; + + case VIA_DDRA: + if (m_ddr_a != data) + { + m_ddr_a = data; + + output_pa(); + } + break; + + case VIA_T1CL: + case VIA_T1LL: + m_t1ll = data; + break; + + case VIA_T1LH: + m_t1lh = data; + clear_int(INT_T1); + break; + + case VIA_T1CH: + m_t1ch = m_t1lh = data; + m_t1cl = m_t1ll; + + clear_int(INT_T1); + + m_t1_pb7 = 0; + + if (T1_SET_PB7(m_acr)) + { + output_pb(); + } + + m_t1->adjust(clocks_to_attotime(TIMER1_VALUE + IFR_DELAY)); + m_t1_active = 1; + break; + + case VIA_T2CL: + m_t2ll = data; + break; + + case VIA_T2CH: + m_t2ch = m_t2lh = data; + m_t2cl = m_t2ll; + + clear_int(INT_T2); + + if (!T2_COUNT_PB6(m_acr)) + { + m_t2->adjust(clocks_to_attotime(TIMER2_VALUE + IFR_DELAY)); + m_t2_active = 1; + } + else + { + m_t2->adjust(clocks_to_attotime(TIMER2_VALUE)); + m_t2_active = 1; + m_time2 = machine().time(); + } + break; + + case VIA_SR: + m_sr = data; + m_shift_counter=0; + clear_int(INT_SR); + if (SO_O2_CONTROL(m_acr)) + { + m_shift_timer->adjust(clocks_to_attotime(2)); + } + if (SO_T2_RATE(m_acr) || SO_T2_CONTROL(m_acr)) + { + m_shift_timer->adjust(clocks_to_attotime((m_t2ll + 2)*2)); + } + break; + + case VIA_PCR: + m_pcr = data; + + if (TRACE_VIA) + { + logerror("%s:6522VIA chip %s: PCR = %02X\n", machine().describe_context(), tag(), data); + } + + if (CA2_FIX_OUTPUT(data) && m_out_ca2 != CA2_OUTPUT_LEVEL(data)) + { + m_out_ca2 = CA2_OUTPUT_LEVEL(data); + m_ca2_handler(m_out_ca2); + } + + if (CB2_FIX_OUTPUT(data) && m_out_cb2 != CB2_OUTPUT_LEVEL(data)) + { + m_out_cb2 = CB2_OUTPUT_LEVEL(data); + m_cb2_handler(m_out_cb2); + } + break; + + case VIA_ACR: + { + UINT16 counter1 = get_counter1_value(); + m_acr = data; + + output_pb(); + + if (T1_CONTINUOUS(data)) + { + m_t1->adjust(clocks_to_attotime(counter1 + IFR_DELAY)); + m_t1_active = 1; + } + } + break; + + case VIA_IER: + if (data & 0x80) + { + m_ier |= data & 0x7f; + } + else + { + m_ier &= ~(data & 0x7f); + } + + output_irq(); + break; + + case VIA_IFR: + if (data & INT_ANY) + { + data = 0x7f; + } + clear_int(data); + break; + } +} + +void via6522_device::write_pa(int line, int state) +{ + if (state) + m_in_a |= (1 << line); + else + m_in_a &= ~(1 << line); +} + +WRITE8_MEMBER( via6522_device::write_pa ) +{ + m_in_a = data; +} + +/*------------------------------------------------- + ca1_w - interface setting VIA port CA1 input +-------------------------------------------------*/ + +WRITE_LINE_MEMBER( via6522_device::write_ca1 ) +{ + if (m_in_ca1 != state) + { + m_in_ca1 = state; + + if (TRACE_VIA) + logerror("%s:6522VIA chip %s: CA1 = %02X\n", machine().describe_context(), tag(), m_in_ca1); + + if ((m_in_ca1 && CA1_LOW_TO_HIGH(m_pcr)) || (!m_in_ca1 && CA1_HIGH_TO_LOW(m_pcr))) + { + if (PA_LATCH_ENABLE(m_acr)) + { + m_latch_a = input_pa(); + } + + set_int(INT_CA1); + + if (!m_out_ca2 && CA2_AUTO_HS(m_pcr)) + { + m_out_ca2 = 1; + m_ca2_handler(m_out_ca2); + } + } + } +} + + +/*------------------------------------------------- + ca2_w - interface setting VIA port CA2 input +-------------------------------------------------*/ + +WRITE_LINE_MEMBER( via6522_device::write_ca2 ) +{ + if (m_in_ca2 != state) + { + m_in_ca2 = state; + + if (CA2_INPUT(m_pcr)) + { + if ((m_in_ca2 && CA2_LOW_TO_HIGH(m_pcr)) || (!m_in_ca2 && CA2_HIGH_TO_LOW(m_pcr))) + { + set_int(INT_CA2); + } + } + } +} + +void via6522_device::write_pb(int line, int state) +{ + if (state) + m_in_b |= (1 << line); + else + m_in_b &= ~(1 << line); +} + +WRITE8_MEMBER( via6522_device::write_pb ) +{ + m_in_b = data; +} + +/*------------------------------------------------- + cb1_w - interface setting VIA port CB1 input +-------------------------------------------------*/ + +WRITE_LINE_MEMBER( via6522_device::write_cb1 ) +{ + if (m_in_cb1 != state) + { + m_in_cb1 = state; + + if ((m_in_cb1 && CB1_LOW_TO_HIGH(m_pcr)) || (!m_in_cb1 && CB1_HIGH_TO_LOW(m_pcr))) + { + if (PB_LATCH_ENABLE(m_acr)) + { + m_latch_b = input_pb(); + } + + if (SO_EXT_CONTROL(m_acr)) + { + shift_out(); + } + + if (SI_EXT_CONTROL(m_acr)) + { + shift_in(); + } + + set_int(INT_CB1); + + if (!m_out_cb2 && CB2_AUTO_HS(m_pcr)) + { + m_out_cb2 = 1; + m_cb2_handler(1); + } + } + } +} + + +/*------------------------------------------------- + cb2_w - interface setting VIA port CB2 input +-------------------------------------------------*/ + +WRITE_LINE_MEMBER( via6522_device::write_cb2 ) +{ + if (m_in_cb2 != state) + { + m_in_cb2 = state; + + if (CB2_INPUT(m_pcr)) + { + if ((m_in_cb2 && CB2_LOW_TO_HIGH(m_pcr)) || (!m_in_cb2 && CB2_HIGH_TO_LOW(m_pcr))) + { + set_int(INT_CB2); + } + } + } +} |