diff options
author | 2015-09-13 08:41:44 +0200 | |
---|---|---|
committer | 2015-09-13 08:41:44 +0200 | |
commit | f88cefad27a1737c76e09d99c9fb43e173506081 (patch) | |
tree | 2d8167d03579c46e226471747eb4407bd00ed6fa /src/devices/machine/z80pio.c | |
parent | e92ac9e0fa8e99869894bea00589bbb526be30aa (diff) |
Move all devices into separate part of src tree (nw)
Diffstat (limited to 'src/devices/machine/z80pio.c')
-rw-r--r-- | src/devices/machine/z80pio.c | 809 |
1 files changed, 809 insertions, 0 deletions
diff --git a/src/devices/machine/z80pio.c b/src/devices/machine/z80pio.c new file mode 100644 index 00000000000..6463adc8fb7 --- /dev/null +++ b/src/devices/machine/z80pio.c @@ -0,0 +1,809 @@ +// license:BSD-3-Clause +// copyright-holders:Curt Coder +/*************************************************************************** + + Zilog Z80 Parallel Input/Output Controller implementation + +***************************************************************************/ + +/* + + TODO: + + - if port A is bidirectional, port B does not issue interrupts in bit mode + +*/ + +#include "emu.h" +#include "z80pio.h" +#include "cpu/z80/z80daisy.h" + + +//************************************************************************** +// CONSTANTS +//************************************************************************** + +#define LOG 0 + + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +// device type definition +const device_type Z80PIO = &device_creator<z80pio_device>; + +//------------------------------------------------- +// z80pio_device - constructor +//------------------------------------------------- + +z80pio_device::z80pio_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : + device_t(mconfig, Z80PIO, "Z80 PIO", tag, owner, clock, "z80pio", __FILE__), + device_z80daisy_interface(mconfig, *this), + m_out_int_cb(*this), + m_in_pa_cb(*this), + m_out_pa_cb(*this), + m_out_ardy_cb(*this), + m_in_pb_cb(*this), + m_out_pb_cb(*this), + m_out_brdy_cb(*this) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void z80pio_device::device_start() +{ + m_port[PORT_A].start(this, PORT_A); + m_port[PORT_B].start(this, PORT_B); + + // resolve callbacks + m_out_int_cb.resolve_safe(); + m_in_pa_cb.resolve_safe(0); + m_out_pa_cb.resolve_safe(); + m_out_ardy_cb.resolve_safe(); + m_in_pb_cb.resolve_safe(0); + m_out_pb_cb.resolve_safe(); + m_out_brdy_cb.resolve_safe(); +} + + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void z80pio_device::device_reset() +{ + // loop over ports + for (int index = PORT_A; index < PORT_COUNT; index++) + m_port[index].reset(); +} + + + +//************************************************************************** +// DAISY CHAIN INTERFACE +//************************************************************************** + +//------------------------------------------------- +// z80daisy_irq_state - return the overall IRQ +// state for this device +//------------------------------------------------- + +int z80pio_device::z80daisy_irq_state() +{ + int state = 0; + + for (int index = PORT_A; index < PORT_COUNT; index++) + { + pio_port &port = m_port[index]; + + if (port.m_ius) + { + // interrupt under service + return Z80_DAISY_IEO; + } + else if (port.m_ie && port.m_ip) + { + // interrupt pending + state = Z80_DAISY_INT; + } + } + + return state; +} + + +//------------------------------------------------- +// z80daisy_irq_ack - acknowledge an IRQ and +// return the appropriate vector +//------------------------------------------------- + +int z80pio_device::z80daisy_irq_ack() +{ + for (int index = PORT_A; index < PORT_COUNT; index++) + { + pio_port &port = m_port[index]; + + if (port.m_ip) + { + if (LOG) logerror("Z80PIO '%s' Port %c Interrupt Acknowledge\n", tag(), 'A' + index); + + // clear interrupt pending flag + port.m_ip = false; + + // set interrupt under service flag + port.m_ius = true; + + check_interrupts(); + + return port.m_vector; + } + } + + //logerror("z80pio_irq_ack: failed to find an interrupt to ack!\n"); + + return 0; +} + + +//------------------------------------------------- +// z80daisy_irq_reti - clear the interrupt +// pending state to allow other interrupts through +//------------------------------------------------- + +void z80pio_device::z80daisy_irq_reti() +{ + for (int index = PORT_A; index < PORT_COUNT; index++) + { + pio_port &port = m_port[index]; + + if (port.m_ius) + { + if (LOG) logerror("Z80PIO '%s' Port %c Return from Interrupt\n", tag(), 'A' + index); + + // clear interrupt under service flag + port.m_ius = false; + check_interrupts(); + + return; + } + } + + //logerror("z80pio_irq_reti: failed to find an interrupt to clear IEO on!\n"); +} + + + +//************************************************************************** +// READ/WRITE HANDLERS +//************************************************************************** + +//------------------------------------------------- +// read - register read +//------------------------------------------------- + +READ8_MEMBER( z80pio_device::read ) +{ + int index = BIT(offset, 0); + return BIT(offset, 1) ? control_read() : data_read(index); +} + +//------------------------------------------------- +// write - register write +//------------------------------------------------- + +WRITE8_MEMBER( z80pio_device::write ) +{ + int index = BIT(offset, 0); + BIT(offset, 1) ? control_write(index, data) : data_write(index, data); +} + +//------------------------------------------------- +// read_alt - register read +//------------------------------------------------- + +READ8_MEMBER( z80pio_device::read_alt ) +{ + int index = BIT(offset, 1); + return BIT(offset, 0) ? control_read() : data_read(index); +} + +//------------------------------------------------- +// write_alt - register write +//------------------------------------------------- + +WRITE8_MEMBER( z80pio_device::write_alt ) +{ + int index = BIT(offset, 1); + BIT(offset, 0) ? control_write(index, data) : data_write(index, data); +} + + + +//************************************************************************** +// DEVICE-LEVEL IMPLEMENTATION +//************************************************************************** + +//------------------------------------------------- +// control_read - control register read +//------------------------------------------------- + +UINT8 z80pio_device::control_read() +{ + return (m_port[PORT_A].m_icw & 0xc0) | (m_port[PORT_B].m_icw >> 4); +} + + +//------------------------------------------------- +// check_interrupts - update the interrupt state +// over all ports +//------------------------------------------------- + +void z80pio_device::check_interrupts() +{ + int state = CLEAR_LINE; + bool ius = (m_port[PORT_A].m_ius || m_port[PORT_B].m_ius); + + for (int index = PORT_A; index < PORT_COUNT; index++) + { + if (LOG) logerror("Z80PIO '%s' Port %c IE %s IP %s IUS %s\n", tag(), 'A' + index, m_port[index].m_ie ? "1":"0", m_port[index].m_ip ? "1":"0", m_port[index].m_ius ? "1":"0"); + + if (!ius && m_port[index].m_ie && m_port[index].m_ip) + { + state = ASSERT_LINE; + } + } + + if (LOG) logerror("Z80PIO '%s' INT %u\n", tag(), state); + + m_out_int_cb(state); +} + + + +//************************************************************************** +// PORT-LEVEL IMPLEMENTATION +//************************************************************************** + +//------------------------------------------------- +// pio_port - constructor +//------------------------------------------------- + +z80pio_device::pio_port::pio_port() : + m_device(NULL), + m_index(0), + m_mode(0), + m_next_control_word(0), + m_input(0), + m_output(0), + m_ior(0), + m_rdy(false), + m_stb(false), + m_ie(false), + m_ip(false), + m_ius(false), + m_icw(0), + m_vector(0), + m_mask(0), + m_match(false) +{ +} + + +//------------------------------------------------- +// start - set up a port during device startup +//------------------------------------------------- + +void z80pio_device::pio_port::start(z80pio_device *device, int index) +{ + m_device = device; + m_index = index; + + // register for state saving + m_device->save_item(NAME(m_mode), m_index); + m_device->save_item(NAME(m_next_control_word), m_index); + m_device->save_item(NAME(m_input), m_index); + m_device->save_item(NAME(m_output), m_index); + m_device->save_item(NAME(m_ior), m_index); + m_device->save_item(NAME(m_rdy), m_index); + m_device->save_item(NAME(m_stb), m_index); + m_device->save_item(NAME(m_ie), m_index); + m_device->save_item(NAME(m_ip), m_index); + m_device->save_item(NAME(m_ius), m_index); + m_device->save_item(NAME(m_icw), m_index); + m_device->save_item(NAME(m_vector), m_index); + m_device->save_item(NAME(m_mask), m_index); + m_device->save_item(NAME(m_match), m_index); +} + + +//------------------------------------------------- +// reset - reset a port during device reset +//------------------------------------------------- + +void z80pio_device::pio_port::reset() +{ + // set mode 1 + set_mode(MODE_INPUT); + + // reset interrupt enable flip-flops + m_icw &= ~ICW_ENABLE_INT; + m_ie = false; + m_ip = false; + m_ius = false; + m_match = false; + + // reset all bits of the data I/O register + m_ior = 0; + + // set all bits of the mask control register + m_mask = 0xff; + + // reset output register + m_output = 0; + + // clear ready line + set_rdy(false); +} + + +//------------------------------------------------- +// trigger_interrupt - trigger an interrupt from +// this port +//------------------------------------------------- + +void z80pio_device::pio_port::trigger_interrupt() +{ + m_ip = true; + if (LOG) logerror("Z80PIO '%s' Port %c Transfer Mode Interrupt Pending\n", m_device->tag(), 'A' + m_index); + + check_interrupts(); +} + + +//------------------------------------------------- +// set_rdy - set the port's RDY line +//------------------------------------------------- + +void z80pio_device::pio_port::set_rdy(bool state) +{ + if (m_rdy == state) return; + + if (LOG) logerror("Z80PIO '%s' Port %c Ready: %u\n", m_device->tag(), 'A' + m_index, state); + + m_rdy = state; + if (m_index == PORT_A) + m_device->m_out_ardy_cb(state); + else + m_device->m_out_brdy_cb(state); +} + + +//------------------------------------------------- +// set_mode - set the port's mode +//------------------------------------------------- + +void z80pio_device::pio_port::set_mode(int mode) +{ + if (LOG) logerror("Z80PIO '%s' Port %c Mode: %u\n", m_device->tag(), 'A' + m_index, mode); + + switch (mode) + { + case MODE_OUTPUT: + // enable data output + if (m_index == PORT_A) + m_device->m_out_pa_cb((offs_t)0, m_output); + else + m_device->m_out_pb_cb((offs_t)0, m_output); + + // assert ready line + set_rdy(true); + + // set mode register + m_mode = mode; + break; + + case MODE_INPUT: + // set mode register + m_mode = mode; + break; + + case MODE_BIDIRECTIONAL: + if (m_index == PORT_B) + { + logerror("Z80PIO '%s' Port %c Invalid Mode: %u!\n", m_device->tag(), 'A' + m_index, mode); + } + else + { + // set mode register + m_mode = mode; + } + break; + + case MODE_BIT_CONTROL: + if ((m_index == PORT_A) || (m_device->m_port[PORT_A].m_mode != MODE_BIDIRECTIONAL)) + { + // clear ready line + set_rdy(false); + } + + // disable interrupts until IOR is written + m_ie = false; + check_interrupts(); + + // set logic equation to false + m_match = false; + + // next word is I/O register + m_next_control_word = IOR; + + // set mode register + m_mode = mode; + break; + } +} + + +//------------------------------------------------- +// strobe - strobe data in/out of the port +//------------------------------------------------- + +void z80pio_device::pio_port::strobe(bool state) +{ + if (LOG) logerror("Z80PIO '%s' Port %c Strobe: %u\n", m_device->tag(), 'A' + m_index, state); + + if (m_device->m_port[PORT_A].m_mode == MODE_BIDIRECTIONAL) + { + if (m_rdy) // port ready + { + if (m_stb && !state) // falling edge + { + if (m_index == PORT_A) + m_device->m_out_pa_cb((offs_t)0, m_output); + else + m_device->m_port[PORT_A].m_input = m_device->m_in_pa_cb(0); + } + else if (!m_stb && state) // rising edge + { + trigger_interrupt(); + + // clear ready line + set_rdy(false); + } + } + } + else + { + switch (m_mode) + { + case MODE_OUTPUT: + if (m_rdy) + { + if (!m_stb && state) // rising edge + { + trigger_interrupt(); + + // clear ready line + set_rdy(false); + } + } + break; + + case MODE_INPUT: + if (!state) + { + // input port data + if (m_index == PORT_A) + m_input = m_device->m_in_pa_cb(0); + else + m_input = m_device->m_in_pb_cb(0); + } + else if (!m_stb && state) // rising edge + { + trigger_interrupt(); + + // clear ready line + set_rdy(false); + } + break; + } + } + + m_stb = state; +} + + +//------------------------------------------------- +// read - port I/O read +//------------------------------------------------- + +UINT8 z80pio_device::pio_port::read() +{ + UINT8 data = 0xff; + + switch (m_mode) + { + case MODE_OUTPUT: + data = m_output; + break; + + case MODE_BIDIRECTIONAL: + if (m_index == PORT_A) + data = m_output; + break; + + case MODE_BIT_CONTROL: + data = m_ior | (m_output & (m_ior ^ 0xff)); + break; + } + + return data; +} + + +//------------------------------------------------- +// write - port I/O write +//------------------------------------------------- + +void z80pio_device::pio_port::write(UINT8 data) +{ + if (m_mode == MODE_BIT_CONTROL) + { + // latch data + m_input = data; + + // fetch input data (ignore output lines) + UINT8 data = (m_input & m_ior) | (m_output & ~m_ior); + UINT8 mask = ~m_mask; + bool match = false; + + data &= mask; + + if ((m_icw & 0x60) == 0 && data != mask) match = true; + else if ((m_icw & 0x60) == 0x20 && data != 0) match = true; + else if ((m_icw & 0x60) == 0x40 && data == 0) match = true; + else if ((m_icw & 0x60) == 0x60 && data == mask) match = true; + + if (!m_match && match && !m_ius) + { + // trigger interrupt + m_ip = true; + if (LOG) logerror("Z80PIO '%s' Port %c Bit Control Mode Interrupt Pending\n", m_device->tag(), 'A' + m_index); + } + + m_match = match; + + check_interrupts(); + } +} + + +//------------------------------------------------- +// control_write - control register write +//------------------------------------------------- + +void z80pio_device::pio_port::control_write(UINT8 data) +{ + switch (m_next_control_word) + { + case ANY: + if (!BIT(data, 0)) + { + // load interrupt vector + m_vector = data; + if (LOG) logerror("Z80PIO '%s' Port %c Interrupt Vector: %02x\n", m_device->tag(), 'A' + m_index, data); + + // set interrupt enable + m_icw |= ICW_ENABLE_INT; + m_ie = true; + check_interrupts(); + } + else + { + switch (data & 0x0f) + { + case 0x0f: // select operating mode + set_mode(data >> 6); + break; + + case 0x07: // set interrupt control word + m_icw = data; + + if (LOG) + { + logerror("Z80PIO '%s' Port %c Interrupt Enable: %u\n", m_device->tag(), 'A' + m_index, BIT(data, 7)); + logerror("Z80PIO '%s' Port %c Logic: %s\n", m_device->tag(), 'A' + m_index, BIT(data, 6) ? "AND" : "OR"); + logerror("Z80PIO '%s' Port %c Active %s\n", m_device->tag(), 'A' + m_index, BIT(data, 5) ? "High" : "Low"); + logerror("Z80PIO '%s' Port %c Mask Follows: %u\n", m_device->tag(), 'A' + m_index, BIT(data, 4)); + } + + if (m_icw & ICW_MASK_FOLLOWS) + { + // disable interrupts until mask is written + m_ie = false; + + // reset pending interrupts + m_ip = false; + check_interrupts(); + + // set logic equation to false + m_match = false; + + // next word is mask control + m_next_control_word = MASK; + } + else + { + // set interrupt enable + m_ie = BIT(m_icw, 7) ? true : false; + check_interrupts(); + } + break; + + case 0x03: // set interrupt enable flip-flop + m_icw = (data & 0x80) | (m_icw & 0x7f); + if (LOG) logerror("Z80PIO '%s' Port %c Interrupt Enable: %u\n", m_device->tag(), 'A' + m_index, BIT(data, 7)); + + // set interrupt enable + m_ie = BIT(m_icw, 7) ? true : false; + check_interrupts(); + break; + + default: + logerror("Z80PIO '%s' Port %c Invalid Control Word: %02x!\n", m_device->tag(), 'A' + m_index, data); + } + } + break; + + case IOR: // data direction register + m_ior = data; + if (LOG) logerror("Z80PIO '%s' Port %c IOR: %02x\n", m_device->tag(), 'A' + m_index, data); + + // set interrupt enable + m_ie = BIT(m_icw, 7) ? true : false; + check_interrupts(); + + // next word is any + m_next_control_word = ANY; + break; + + case MASK: // interrupt mask + m_mask = data; + if (LOG) logerror("Z80PIO '%s' Port %c Mask: %02x\n", m_device->tag(), 'A' + m_index, data); + + // set interrupt enable + m_ie = BIT(m_icw, 7) ? true : false; + check_interrupts(); + + // next word is any + m_next_control_word = ANY; + break; + } +} + + +//------------------------------------------------- +// data_read - data register read +//------------------------------------------------- + +UINT8 z80pio_device::pio_port::data_read() +{ + UINT8 data = 0; + + switch (m_mode) + { + case MODE_OUTPUT: + data = m_output; + break; + + case MODE_INPUT: + if (!m_stb) + { + // input port data + if (m_index == PORT_A) + m_input = m_device->m_in_pa_cb(0); + else + m_input = m_device->m_in_pb_cb(0); + } + + data = m_input; + + // clear ready line + set_rdy(false); + + // assert ready line + set_rdy(true); + break; + + case MODE_BIDIRECTIONAL: + data = m_input; + + // clear ready line + m_device->m_port[PORT_B].set_rdy(false); + + // assert ready line + m_device->m_port[PORT_B].set_rdy(true); + break; + + case MODE_BIT_CONTROL: + // input port data + if (m_index == PORT_A) + m_input = m_device->m_in_pa_cb(0); + else + m_input = m_device->m_in_pb_cb(0); + + data = (m_input & m_ior) | (m_output & (m_ior ^ 0xff)); + break; + } + + return data; +} + + +//------------------------------------------------- +// data_write - data register write +//------------------------------------------------- + +void z80pio_device::pio_port::data_write(UINT8 data) +{ + switch (m_mode) + { + case MODE_OUTPUT: + // clear ready line + set_rdy(false); + + // latch output data + m_output = data; + + // output data to port + if (m_index == PORT_A) + m_device->m_out_pa_cb((offs_t)0, m_output); + else + m_device->m_out_pb_cb((offs_t)0, m_output); + + // assert ready line + set_rdy(true); + break; + + case MODE_INPUT: + // latch output data + m_output = data; + break; + + case MODE_BIDIRECTIONAL: + // clear ready line + set_rdy(false); + + // latch output data + m_output = data; + + if (!m_stb) + { + // output data to port + if (m_index == PORT_A) + m_device->m_out_pa_cb((offs_t)0, data); + else + m_device->m_out_pb_cb((offs_t)0, data); + } + + // assert ready line + set_rdy(true); + break; + + case MODE_BIT_CONTROL: + // latch output data + m_output = data; + + // output data to port + if (m_index == PORT_A) + m_device->m_out_pa_cb((offs_t)0, m_ior | (m_output & (m_ior ^ 0xff))); + else + m_device->m_out_pb_cb((offs_t)0, m_ior | (m_output & (m_ior ^ 0xff))); + break; + } +} |