// license:BSD-3-Clause // copyright-holders:smf /* * PlayStation Serial I/O emulator * * Copyright 2003-2011 smf * */ #include "emu.h" #include "sio.h" #define LOG_TIMER (1U << 1) #define VERBOSE ( 0 ) #include "logmacro.h" DEFINE_DEVICE_TYPE(PSX_SIO0, psxsio0_device, "psxsio0", "Sony PSX SIO-0") DEFINE_DEVICE_TYPE(PSX_SIO1, psxsio1_device, "psxsio1", "Sony PSX SIO-1") psxsio0_device::psxsio0_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : psxsio_device(mconfig, PSX_SIO0, tag, owner, clock) { } psxsio1_device::psxsio1_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : psxsio_device(mconfig, PSX_SIO1, tag, owner, clock) { } psxsio_device::psxsio_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, type, tag, owner, clock), m_status(SIO_STATUS_TX_EMPTY | SIO_STATUS_TX_RDY), m_mode(0), m_control(0), m_baud(0), m_rxd(1), m_tx_data(0), m_rx_data(0), m_tx_shift(0), m_rx_shift(0), m_tx_bits(0), m_rx_bits(0), m_timer(nullptr), m_irq_handler(*this), m_sck_handler(*this), m_txd_handler(*this), m_dtr_handler(*this), m_rts_handler(*this) { } void psxsio_device::device_post_load() { sio_timer_adjust(); } void psxsio_device::device_start() { m_timer = timer_alloc(FUNC( psxsio_device::sio_tick ), this); m_mode = 0; m_control = 0; m_baud = 0; m_rx_data = 0; m_tx_data = 0; m_rx_shift = 0; m_tx_shift = 0; m_rx_bits = 0; m_tx_bits = 0; save_item(NAME(m_status)); save_item(NAME(m_mode)); save_item(NAME(m_control)); save_item(NAME(m_baud)); save_item(NAME(m_rxd)); save_item(NAME(m_rx_data)); save_item(NAME(m_tx_data)); save_item(NAME(m_rx_shift)); save_item(NAME(m_tx_shift)); save_item(NAME(m_rx_bits)); save_item(NAME(m_tx_bits)); } void psxsio_device::sio_interrupt() { LOG("sio_interrupt\n"); m_status |= SIO_STATUS_IRQ; m_irq_handler(1); } void psxsio_device::sio_timer_adjust() { attotime n_time; if( ( m_status & SIO_STATUS_TX_EMPTY ) == 0 || m_tx_bits != 0 ) { int n_prescaler; switch( m_mode & 3 ) { case 1: n_prescaler = 1; break; case 2: n_prescaler = 16; break; case 3: n_prescaler = 64; break; default: n_prescaler = 0; break; } if( m_baud != 0 && n_prescaler != 0 ) { n_time = attotime::from_hz(33868800) * (n_prescaler * m_baud); LOGMASKED( LOG_TIMER, "sio_timer_adjust = %s ( %d x %d )\n", n_time.as_string(), n_prescaler, m_baud ); } else { n_time = attotime::never; logerror( "sio_timer_adjust invalid baud rate ( %d x %d )\n", n_prescaler, m_baud ); } } else { n_time = attotime::never; LOG( "sio_timer_adjust finished\n" ); } m_timer->adjust( n_time ); } TIMER_CALLBACK_MEMBER( psxsio_device::sio_tick ) { LOGMASKED( LOG_TIMER, "sio tick\n" ); if( m_tx_bits == 0 && ( m_control & SIO_CONTROL_TX_ENA ) != 0 && ( m_status & SIO_STATUS_TX_EMPTY ) == 0 ) { m_tx_bits = 8; m_tx_shift = m_tx_data; if( type() == PSX_SIO0 ) { m_rx_bits = 8; m_rx_shift = 0; } m_status |= SIO_STATUS_TX_EMPTY; m_status |= SIO_STATUS_TX_RDY; } if( m_tx_bits != 0 ) { if( type() == PSX_SIO0 ) { m_sck_handler(0); } m_txd_handler( m_tx_shift & 1 ); m_tx_shift >>= 1; m_tx_bits--; if( type() == PSX_SIO0 ) { m_sck_handler(1); } if( m_tx_bits == 0 && ( m_control & SIO_CONTROL_TX_IENA ) != 0 ) { sio_interrupt(); } } if( m_rx_bits != 0 ) { m_rx_shift = ( m_rx_shift >> 1 ) | ( m_rxd << 7 ); m_rx_bits--; if( m_rx_bits == 0 ) { if( ( m_status & SIO_STATUS_RX_RDY ) != 0 ) { m_status |= SIO_STATUS_OVERRUN; } else { m_rx_data = m_rx_shift; m_status |= SIO_STATUS_RX_RDY; } if( ( m_control & SIO_CONTROL_RX_IENA ) != 0 ) { sio_interrupt(); } } } sio_timer_adjust(); } void psxsio_device::write(offs_t offset, uint32_t data, uint32_t mem_mask) { switch( offset % 4 ) { case 0: LOG( "%s: psx_sio_w data %02x (%08x)\n", machine().describe_context(), data, mem_mask ); m_tx_data = data; m_status &= ~( SIO_STATUS_TX_RDY ); m_status &= ~( SIO_STATUS_TX_EMPTY ); sio_timer_adjust(); break; case 1: logerror( "%s: psx_sio_w( %08x, %08x, %08x )\n", machine().describe_context(), offset, data, mem_mask ); break; case 2: if( ACCESSING_BITS_0_15 ) { m_mode = data & 0xffff; LOG( "%s: psx_sio_w mode %04x\n", machine().describe_context(), data & 0xffff ); } if( ACCESSING_BITS_16_31 ) { LOG( "%s: psx_sio_w control %04x\n", machine().describe_context(), data >> 16 ); m_control = data >> 16; if( ( m_control & SIO_CONTROL_RESET ) != 0 ) { LOG( "%s: psx_sio_w reset\n", machine().describe_context() ); m_status |= SIO_STATUS_TX_EMPTY | SIO_STATUS_TX_RDY; m_status &= ~( SIO_STATUS_RX_RDY | SIO_STATUS_OVERRUN | SIO_STATUS_IRQ ); m_irq_handler(0); // toggle DTR to reset controllers, Star Ocean 2, at least, requires it // the precise mechanism of the reset is unknown // maybe it's related to the bottom 2 bits of control which are usually set m_dtr_handler(0); m_dtr_handler(1); m_tx_bits = 0; m_rx_bits = 0; m_txd_handler(1); } if( ( m_control & SIO_CONTROL_IACK ) != 0 ) { LOG( "%s: psx_sio_w iack\n", machine().describe_context() ); m_status &= ~( SIO_STATUS_IRQ ); m_control &= ~( SIO_CONTROL_IACK ); m_irq_handler(0); } if( ( m_control & SIO_CONTROL_DTR ) != 0 ) { m_dtr_handler(0); } else { m_dtr_handler(1); } } break; case 3: if( ACCESSING_BITS_0_15 ) { logerror( "%s: psx_sio_w( %08x, %08x, %08x )\n", machine().describe_context(), offset, data, mem_mask ); } if( ACCESSING_BITS_16_31 ) { m_baud = data >> 16; LOG( "%s: psx_sio_w baud %04x\n", machine().describe_context(), data >> 16 ); } break; default: logerror( "%s: psx_sio_w( %08x, %08x, %08x )\n", machine().describe_context(), offset, data, mem_mask ); break; } } uint32_t psxsio_device::read(offs_t offset, uint32_t mem_mask) { uint32_t data; switch( offset % 4 ) { case 0: data = m_rx_data; m_status &= ~( SIO_STATUS_RX_RDY ); m_rx_data = 0xff; LOG( "%s: psx_sio_r data %02x (%08x)\n", machine().describe_context(), data, mem_mask ); break; case 1: data = m_status; if( ACCESSING_BITS_0_15 ) { LOG( "%s: psx_sio_r status %04x\n", machine().describe_context(), data & 0xffff ); } if( ACCESSING_BITS_16_31 ) { logerror( "%s: psx_sio_r( %08x, %08x ) %08x\n", machine().describe_context(), offset, mem_mask, data ); } break; case 2: data = ( m_control << 16 ) | m_mode; if( ACCESSING_BITS_0_15 ) { LOG( "%s: psx_sio_r mode %04x\n", machine().describe_context(), data & 0xffff ); } if( ACCESSING_BITS_16_31 ) { LOG( "%s: psx_sio_r control %04x\n", machine().describe_context(), data >> 16 ); } break; case 3: data = m_baud << 16; if( ACCESSING_BITS_0_15 ) { logerror( "%s: psx_sio_r( %08x, %08x ) %08x\n", machine().describe_context(), offset, mem_mask, data ); } if( ACCESSING_BITS_16_31 ) { LOG( "%s: psx_sio_r baud %04x\n", machine().describe_context(), data >> 16 ); } break; default: data = 0; logerror( "%s: psx_sio_r( %08x, %08x ) %08x\n", machine().describe_context(), offset, mem_mask, data ); break; } return data; } void psxsio_device::write_rxd(int state) { m_rxd = state; } void psxsio_device::write_dsr(int state) { if (state) { m_status &= ~SIO_STATUS_DSR; } else if ((m_status & SIO_STATUS_DSR) == 0) { m_status |= SIO_STATUS_DSR; if( ( m_control & SIO_CONTROL_DSR_IENA ) != 0 ) { sio_interrupt(); } } }