diff options
Diffstat (limited to 'io.c')
| -rw-r--r-- | io.c | 71 |
1 files changed, 68 insertions, 3 deletions
@@ -1506,6 +1506,16 @@ void io_adjust_cycles(io_port * port, uint32_t current_cycle, uint32_t deduction port->device.mouse.ready_cycle -= deduction; } } + for (int i = 0; i < 8; i++) + { + if (port->slow_rise_start[i] != CYCLE_NEVER) { + if (port->slow_rise_start[i] >= deduction) { + port->slow_rise_start[i] -= deduction; + } else { + port->slow_rise_start[i] = CYCLE_NEVER; + } + } + } if (last_poll_cycle >= deduction) { last_poll_cycle -= deduction; } else { @@ -1623,6 +1633,25 @@ enum { KB_WRITE }; +void io_control_write(io_port *port, uint8_t value, uint32_t current_cycle) +{ + uint8_t changes = value ^ port->control; + if (changes) { + for (int i = 0; i < 8; i++) + { + if (!(value & 1 << i) && !(port->output & 1 << i)) { + //port switched from output to input and the output value was 0 + //since there is a weak pull-up on input pins, this will lead + //to a slow rise from 0 to 1 if the pin isn't being externally driven + port->slow_rise_start[i] = current_cycle; + } else { + port->slow_rise_start[i] = CYCLE_NEVER; + } + } + port->control = value; + } +} + void io_data_write(io_port * port, uint8_t value, uint32_t current_cycle) { uint8_t old_output = (port->control & port->output) | (~port->control & 0xFF); @@ -1766,12 +1795,34 @@ uint8_t get_scancode_bytes(io_port *port) return bytes; } +#define SLOW_RISE_DEVICE (30*7) +#define SLOW_RISE_INPUT (12*7) + +static uint8_t get_output_value(io_port *port, uint32_t current_cycle, uint32_t slow_rise_delay) +{ + uint8_t output = (port->control | 0x80) & port->output; + for (int i = 0; i < 8; i++) + { + if (!(port->control & 1 << i)) { + if (port->slow_rise_start[i] != CYCLE_NEVER) { + if (current_cycle - port->slow_rise_start[i] >= slow_rise_delay) { + output |= 1 << i; + } + } else { + output |= 1 << i; + } + } + } + return output; +} + uint8_t io_data_read(io_port * port, uint32_t current_cycle) { + uint8_t output = get_output_value(port, current_cycle, SLOW_RISE_DEVICE); uint8_t control = port->control | 0x80; - uint8_t output = (control & port->output) | (~control & 0xFF); uint8_t th = output & 0x40; uint8_t input; + uint8_t device_driven; if (current_cycle - last_poll_cycle > MIN_POLL_INTERVAL) { process_events(); last_poll_cycle = current_cycle; @@ -1789,6 +1840,7 @@ uint8_t io_data_read(io_port * port, uint32_t current_cycle) } //controller output is logically inverted input = ~input; + device_driven = 0x3F; break; } case IO_GAMEPAD6: @@ -1816,6 +1868,7 @@ uint8_t io_data_read(io_port * port, uint32_t current_cycle) } //controller output is logically inverted input = ~input; + device_driven = 0x3F; break; } case IO_MOUSE: @@ -1875,6 +1928,7 @@ uint8_t io_data_read(io_port * port, uint32_t current_cycle) } input |= ((port->device.mouse.tr_counter & 1) == 0) << 4; } + device_driven = 0x1F; break; } case IO_SATURN_KEYBOARD: @@ -1947,6 +2001,7 @@ uint8_t io_data_read(io_port * port, uint32_t current_cycle) } input |= ((port->device.keyboard.tr_counter & 1) == 0) << 4; } + device_driven = 0x1F; break; } case IO_XBAND_KEYBOARD: @@ -2008,6 +2063,8 @@ uint8_t io_data_read(io_port * port, uint32_t current_cycle) input = 0xF; } input |= ((port->device.keyboard.tr_counter & 1) == 0) << 4; + //this is not strictly correct at all times, but good enough for now + device_driven = 0x1F; } break; } @@ -2018,6 +2075,7 @@ uint8_t io_data_read(io_port * port, uint32_t current_cycle) service_pipe(port); } input = port->input[th ? IO_TH1 : IO_TH0]; + device_driven = 0x3F; break; case IO_GENERIC: if (port->input[IO_TH0] & 0x80 && port->input[IO_STATE] == IO_WRITTEN) @@ -2027,13 +2085,20 @@ uint8_t io_data_read(io_port * port, uint32_t current_cycle) } service_socket(port); input = port->input[IO_TH0]; + device_driven = 0x7F; break; #endif default: - input = 0xFF; + input = 0; + device_driven = 0; break; } - uint8_t value = (input & (~control)) | (port->output & control); + uint8_t value = (input & (~control) & device_driven) | (port->output & control); + //deal with pins that are configured as inputs, but not being actively driven by the device + uint8_t floating = (~device_driven) & (~control); + if (floating) { + value |= get_output_value(port, current_cycle, SLOW_RISE_INPUT) & floating; + } /*if (port->input[GAMEPAD_TH0] || port->input[GAMEPAD_TH1]) { printf ("value: %X\n", value); }*/ |