// license:BSD-3-Clause
// copyright-holders:R. Belmont
/*
* ncr539x.c
*
* NCR 53(CF)94/53(CF)96 SCSI controller
* Includes enhanced features of the AMD 53CF94/96 and compatibles
*
* All new emulation in 2011 by R. Belmont.
*
*/
#include "emu.h"
#include "ncr539x.h"
#define VERBOSE (0)
#define VERBOSE_READS (0)
enum
{
TIMER_539X_COMMAND,
TIMER_539X_END
};
#define MAIN_STATUS_INTERRUPT 0x80
#define MAIN_STATUS_ILLEGAL_OPER 0x40
#define MAIN_STATUS_PARITY_ERROR 0x20
#define MAIN_STATUS_COUNT_TO_ZERO 0x10
#define MAIN_STATUS_GROUP_VALID 0x08
#define MAIN_STATUS_MESSAGE 0x04
#define MAIN_STATUS_CMD_DATA 0x02
#define MAIN_STATUS_IO 0x01
#define IRQ_STATUS_RESET 0x80
#define IRQ_STATUS_INVALID_COMMAND 0x40
#define IRQ_STATUS_DISCONNECTED 0x20
#define IRQ_STATUS_SERVICE_REQUEST 0x10
#define IRQ_STATUS_SUCCESS 0x08
#define IRQ_STATUS_RESELECTED 0x04 // we were reselected as a target
#define IRQ_STATUS_SELECTED_WITH_ATN 0x02 // we were selected as a target with ATN steps
#define IRQ_STATUS_SELECTED 0x01 // we were selected as a target
#define CR2_ALIGN_ENABLE 0x80
#define CR2_FEATURES_ENABLE 0x40
#define CR2_BYTE_ORDER 0x20
#define CR2_TRISTATE_DMA 0x10
#define CR2_SCSI2_ENABLE 0x08
#define CR2_ABORT_ON_PARITY_ERROR 0x04
#define CR2_GENERATE_REGISTER_PARITY 0x02
#define CR2_GENERATE_DATA_PARITY 0x01
#if VERBOSE
#if VERBOSE_READS
static const char *rdregs[16] = {
"Transfer count LSB", // 0
"Transfer count MSB", // 1
"FIFO", // 2
"Command", // 3
"Status", // 4
"Interrupt Status", // 5
"Internal State", // 6
"Current FIFO/Internal State", // 7
"Control Register 1", // 8
"0x9",
"0xA",
"Control Register 2",
"Control Register 3",
"Control Register 4",
"Transfer count HSB/Chip ID",
"0xF"
};
#endif
static const char *wrregs[16] = {
"Start Transfer count LSB",
"Start Transfer count MSB",
"FIFO",
"Command",
"SCSI Destination ID",
"SCSI Timeout",
"Synchronous Transfer Period",
"Synchronous Offset",
"Control Register 1",
"Clock Factor",
"Forced Test Mode",
"Control Register 2",
"Control Register 3",
"Control Register 4",
"Start Transfer count HSB",
"Data Alignment"
};
#endif
// get the length of a SCSI command based on its command byte type
static int get_cmd_len(int cbyte)
{
int group;
group = (cbyte>>5) & 7;
if (group == 0) return 6;
if (group == 1 || group == 2) return 10;
if (group == 5) return 12;
return 6;
}
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
const device_type NCR539X = &device_creator<ncr539x_device>;
//-------------------------------------------------
// ncr539x_device - constructor/destructor
//-------------------------------------------------
ncr539x_device::ncr539x_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
legacy_scsi_host_adapter(mconfig, NCR539X, "539x SCSI", tag, owner, clock, "ncr539x", __FILE__),
m_out_irq_cb(*this),
m_out_drq_cb(*this)
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void ncr539x_device::device_start()
{
legacy_scsi_host_adapter::device_start();
// resolve line callbacks
m_out_irq_cb.resolve_safe();
m_out_drq_cb.resolve_safe();
m_operation_timer = timer_alloc(0, nullptr);
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void ncr539x_device::device_reset()
{
m_fifo_ptr = 0;
m_fifo_read_ptr = 0;
m_irq_status = 0;
m_status = SCSI_PHASE_STATUS;
m_internal_state = 0;
m_buffer_offset = 512;
m_buffer_remaining = 0;
m_dma_size = 0;
m_xfer_count = 0;
m_total_data = 0;
m_selected = false;
m_control1 = m_control2 = m_control3 = m_control4 = 0;
m_chipid_available = false;
m_chipid_lock = false;
m_out_irq_cb(CLEAR_LINE);
m_out_drq_cb(CLEAR_LINE);
}
void ncr539x_device::dma_read_data(int bytes, uint8_t *pData)
{
read_data(pData, bytes);
}
void ncr539x_device::dma_write_data(int bytes, uint8_t *pData)
{
write_data(pData, bytes);
}
void ncr539x_device::device_timer(emu_timer &timer, device_timer_id tid, int param, void *ptr)
{
//printf("539X: device_timer expired, param = %d, m_command = %02x\n", param, m_command);
switch (param)
{
case TIMER_539X_COMMAND:
// if this is a DMA command, raise DRQ now
if (m_command & 0x80)
{
m_out_drq_cb(ASSERT_LINE);
}
switch (m_command & 0x7f)
{
case 0x41: // select without ATN steps
if (select(m_last_id))
{
m_irq_status |= IRQ_STATUS_SERVICE_REQUEST | IRQ_STATUS_SUCCESS;
// we should now be in the command phase
m_status &= ~7; // clear bus phases
m_status |= MAIN_STATUS_INTERRUPT | SCSI_PHASE_COMMAND;
m_fifo_ptr = 0;
m_selected = true;
#if VERBOSE
printf("Selecting w/o ATN, irq_status = %02x, status = %02x!\n", m_irq_status, m_status);
#endif
// if DMA is not enabled, there should already be a command loaded into the FIFO
if (!(m_command & 0x80))
{
exec_fifo();
}
update_fifo_internal_state(0);
}
else
{
#if VERBOSE
printf("Select failed, no device @ ID %d!\n", m_last_id);
#endif
m_status |= MAIN_STATUS_INTERRUPT;
m_irq_status |= IRQ_STATUS_DISCONNECTED;
}
m_out_irq_cb(ASSERT_LINE);
break;
case 0x42: // Select with ATN steps
if (select(m_last_id))
{
m_irq_status |= IRQ_STATUS_SERVICE_REQUEST | IRQ_STATUS_SUCCESS;
// we should now be in the command phase
m_status &= ~7; // clear bus phases
m_status |= MAIN_STATUS_INTERRUPT | SCSI_PHASE_COMMAND;
m_fifo_ptr = 0;
m_selected = true;
#if VERBOSE
printf("Selecting with ATN, irq_status = %02x, status = %02x!\n", m_irq_status, m_status);
#endif
// if DMA is not enabled, there should already be a command loaded into the FIFO
if (!(m_command & 0x80))
{
exec_fifo();
}
update_fifo_internal_state(0);
}
else
{
#if VERBOSE
printf("Select failed, no device @ ID %d!\n", m_last_id);
#endif
m_status |= MAIN_STATUS_INTERRUPT;
m_irq_status |= IRQ_STATUS_DISCONNECTED;
}
m_out_irq_cb(ASSERT_LINE);
break;
case 0x11: // initiator command complete
#if VERBOSE
printf("Initiator command complete\n");
#endif
m_irq_status = IRQ_STATUS_SERVICE_REQUEST;
m_status &= ~7; // clear phase bits
m_status |= MAIN_STATUS_INTERRUPT | SCSI_PHASE_DATAIN; // go to data in phase (?)
m_out_irq_cb(ASSERT_LINE);
// this puts status and message bytes into the FIFO (todo: what are these?)
m_fifo_ptr = 0;
m_xfer_count = 2;
m_buffer_remaining = m_total_data = 0;
m_fifo[0] = 0; // status byte
m_fifo[1] = 0; // message byte
m_selected = false;
update_fifo_internal_state(2);
break;
case 0x12: // message accepted
#if VERBOSE
printf("Message accepted\n");
#endif
m_irq_status = IRQ_STATUS_SERVICE_REQUEST;
m_status |= MAIN_STATUS_INTERRUPT;
m_out_irq_cb(ASSERT_LINE);
break;
default:
fatalerror("539x: Unhandled command %02x\n", m_command);
}
break;
default:
break;
}
}
READ8_MEMBER( ncr539x_device::read )
{
uint8_t rv = 0;
#if VERBOSE
#if VERBOSE_READS
printf("539x: Read @ %s (%02x) (PC=%x) (status %02x irq_status %02x)\n", rdregs[offset], offset, space.device().safe_pc(), m_status, m_irq_status);
#endif
#endif
switch (offset)
{
case 0:
rv = m_xfer_count & 0xff;
break;
case 1:
rv = (m_xfer_count>>8) & 0xff;
break;
case 2: // FIFO
{
uint8_t fifo_bytes = m_fifo_internal_state & 0x1f;
if (!fifo_bytes)
{
rv = 0;
}
else
{
rv = m_fifo[m_fifo_read_ptr++];
m_fifo_read_ptr &= (m_fifo_size-1);
fifo_bytes--;
m_xfer_count--;
update_fifo_internal_state(fifo_bytes);
#if VERBOSE
printf("Read %02x from FIFO[%d], FIFO now contains %d bytes (PC=%x, m_buffer_remaining %x)\n", rv, m_fifo_read_ptr-1, fifo_bytes, space.device().safe_pc(), m_buffer_remaining);
#endif
if (fifo_bytes == 0)
{
// the last transfer command has more data for us
if (m_xfer_count > 0)
{
int fifo_fill_size = m_fifo_size;
if (m_xfer_count < fifo_fill_size)
{
fifo_fill_size = m_xfer_count;
}
assert(m_buffer_offset < m_buffer_size);
assert((m_buffer_offset + fifo_fill_size) <= m_buffer_size);
memcpy(m_fifo, &m_buffer[m_buffer_offset], fifo_fill_size);
m_buffer_offset += fifo_fill_size;
m_buffer_remaining -= fifo_fill_size;
m_fifo_ptr = 0;
update_fifo_internal_state(fifo_fill_size);
#if VERBOSE
printf("Refreshing FIFO (%x remaining from transfer, %x in buffer, %x in total)\n", m_xfer_count, m_buffer_remaining, m_total_data);
#endif
}
else
{
#if VERBOSE
printf("FIFO empty, asserting service request (buffer_remaining %x)\n", m_buffer_remaining);
#endif
m_irq_status = IRQ_STATUS_SERVICE_REQUEST;
m_status &= 0x7; // clear everything but the phase bits
m_status |= MAIN_STATUS_INTERRUPT | MAIN_STATUS_COUNT_TO_ZERO;
m_out_irq_cb(ASSERT_LINE);
// if no data at all, drop the phase
if ((m_buffer_remaining + m_total_data) == 0)
{
#if VERBOSE
printf("Out of data, setting phase STATUS\n");
#endif
m_status &= ~0x7;
m_status |= SCSI_PHASE_STATUS;
}
}
}
}
}
break;
case 3:
rv = m_command;
break;
case 4:
rv = m_status;
break;
case 5:
rv = m_irq_status;
// clear the interrupt state
m_status &= ~MAIN_STATUS_INTERRUPT;
m_out_irq_cb(CLEAR_LINE);
break;
case 6:
rv = m_internal_state;
break;
case 7:
rv = m_fifo_internal_state;
break;
case 8:
rv = m_control1;
break;
case 0xb:
rv = m_control2;
break;
case 0xc:
rv = m_control3;
break;
case 0xd:
rv = m_control4;
break;
case 0xe:
if (m_control2 & CR2_FEATURES_ENABLE)
{
if (m_chipid_available)
{
rv = 0xa2; // 0x12 for CF94, 0xa2 for CF96
}
else
{
rv = (m_xfer_count>>16) & 0xff;
}
}
break;
}
return rv;
}
WRITE8_MEMBER( ncr539x_device::write )
{
#if VERBOSE
//if (offset != 2)
printf("539x: Write %02x @ %s (%02x) (PC=%x)\n", data, wrregs[offset], offset, space.device().safe_pc());
#endif
switch (offset)
{
case 0:
m_dma_size &= 0xff00;
m_dma_size |= data;
break;
case 1:
m_dma_size &= 0x00ff;
m_dma_size |= (data<<8);
break;
case 2: // FIFO
fifo_write(data);
break;
case 3:
m_command = data;
// clear status bits (OK to do here?)
m_status &= ~MAIN_STATUS_INTERRUPT;
m_irq_status = 0;
switch (data & 0x7f)
{
case 0x00: // NOP
m_irq_status = IRQ_STATUS_SUCCESS;
m_status |= MAIN_STATUS_INTERRUPT;
m_out_irq_cb(ASSERT_LINE);
// DMA NOP? allow chip ID
if ((m_command == 0x80) && (!m_chipid_lock))
{
m_chipid_available = true;
}
break;
case 0x01: // Clear FIFO (must not change buffer state)
m_fifo_ptr = 0;
update_fifo_internal_state(0);
m_irq_status = IRQ_STATUS_SUCCESS;
m_status |= MAIN_STATUS_INTERRUPT;
m_out_irq_cb(ASSERT_LINE);
break;
case 0x02: // Reset device
device_reset();
m_irq_status = IRQ_STATUS_SUCCESS;
m_status |= MAIN_STATUS_INTERRUPT;
m_out_irq_cb(ASSERT_LINE);
break;
case 0x03: // Reset SCSI bus
m_status = 0;
m_irq_status = IRQ_STATUS_SUCCESS;
m_status |= MAIN_STATUS_INTERRUPT;
m_out_irq_cb(ASSERT_LINE);
break;
case 0x10: // information transfer (must happen immediately)
m_status &= 0x7; // clear everything but the phase bits
m_status |= MAIN_STATUS_INTERRUPT;
m_irq_status = IRQ_STATUS_SUCCESS;
int phase;
phase = get_phase();
#if VERBOSE
printf("Information transfer: phase %d buffer remaining %x\n", phase, m_buffer_remaining);
#endif
if (phase == SCSI_PHASE_DATAIN) // target -> initiator transfer
{
int amtToGet = m_buffer_size;
// fill the internal sector buffer
if (m_buffer_remaining <= 0)
{
if (m_total_data < m_buffer_size)
{
amtToGet = m_total_data;
}
#if VERBOSE
printf("amtToGet = %x\n", amtToGet);
#endif
if (amtToGet > 0)
{
read_data(m_buffer, amtToGet);
m_total_data -= amtToGet;
m_buffer_offset = 0;
m_buffer_remaining = amtToGet;
}
}
// copy the requested amount into the FIFO
if (amtToGet > 0)
{
if (m_buffer_remaining < m_dma_size)
{
m_dma_size = m_buffer_remaining;
}
int fifo_fill_size = m_fifo_size;
if (m_dma_size < fifo_fill_size)
{
fifo_fill_size = m_dma_size;
}
#if VERBOSE
printf("filling FIFO from buffer[%x] for %x bytes\n", m_buffer_offset, fifo_fill_size);
#endif
memcpy(m_fifo, &m_buffer[m_buffer_offset], fifo_fill_size);
m_buffer_offset += fifo_fill_size;
m_buffer_remaining -= fifo_fill_size;
m_xfer_count = m_dma_size;
m_fifo_ptr = 0;
update_fifo_internal_state(fifo_fill_size);
m_out_drq_cb(ASSERT_LINE);
}
m_status |= MAIN_STATUS_COUNT_TO_ZERO;
#if VERBOSE
printf("Information transfer: put %02x bytes into FIFO (dma size %x) (buffer remaining %x)\n", m_fifo_internal_state & 0x1f, m_dma_size, m_buffer_remaining);
#endif
}
else if (phase == SCSI_PHASE_DATAOUT)
{
m_xfer_count = m_dma_size;
if (m_xfer_count == 0)
{
m_xfer_count = 0x10000;
}
#if VERBOSE
printf("dma_size %x, xfer_count %x\n", m_dma_size, m_xfer_count);
#endif
m_status &= ~MAIN_STATUS_COUNT_TO_ZERO;
m_fifo_ptr = 0;
m_buffer_offset = 0;
m_buffer_remaining = 0;
}
m_out_irq_cb(ASSERT_LINE);
break;
case 0x24: // Terminate steps
#if VERBOSE
printf("Terminate steps\n");
#endif
m_irq_status = IRQ_STATUS_SUCCESS | IRQ_STATUS_DISCONNECTED;
m_status |= MAIN_STATUS_INTERRUPT;
m_out_irq_cb(ASSERT_LINE);
m_fifo_ptr = 0;
update_fifo_internal_state(0);
break;
case 0x27: // Disconnect
#if VERBOSE
printf("Disconnect\n");
#endif
m_irq_status = IRQ_STATUS_SUCCESS;
m_status |= MAIN_STATUS_INTERRUPT;
m_out_irq_cb(ASSERT_LINE);
break;
case 0x44: // Enable selection/reselection
#if VERBOSE
printf("Enable selection/reselection\n");
#endif
m_irq_status = IRQ_STATUS_SUCCESS;
m_status |= MAIN_STATUS_INTERRUPT;
m_out_irq_cb(ASSERT_LINE);
break;
case 0x47: // Reselect with ATN3 steps
if (select(m_last_id))
{
m_irq_status |= IRQ_STATUS_SERVICE_REQUEST | IRQ_STATUS_SUCCESS;
// we should now be in the command phase
m_status &= ~7; // clear bus phases
m_status |= MAIN_STATUS_INTERRUPT | SCSI_PHASE_COMMAND;
m_fifo_ptr = 0;
m_selected = true;
#if VERBOSE
printf("Reselecting with ATN3, irq_status = %02x, status = %02x!\n", m_irq_status, m_status);
#endif
// if DMA is not enabled, there should already be a command loaded into the FIFO
if (!(m_command & 0x80))
{
exec_fifo();
}
update_fifo_internal_state(0);
}
else
{
#if VERBOSE
printf("Reselect with ATN3 failed, no device @ ID %d!\n", m_last_id);
#endif
m_status |= MAIN_STATUS_INTERRUPT;
m_irq_status |= IRQ_STATUS_DISCONNECTED;
}
m_out_irq_cb(ASSERT_LINE);
break;
default: // other commands are not instantaneous
#if VERBOSE
printf("Setting timer for command %02x\n", data);
#endif
// 1x commands happen much faster
if ((m_command & 0x70) == 0x10)
{
m_operation_timer->adjust(attotime::from_hz(65536), TIMER_539X_COMMAND);
}
else
{
m_operation_timer->adjust(attotime::from_hz(16384), TIMER_539X_COMMAND);
}
break;
}
break;
case 4:
m_last_id = data;
break;
case 5:
m_timeout = data;
break;
case 6:
m_sync_xfer_period = data;
break;
case 7:
m_sync_offset = data;
break;
case 8:
m_control1 = data;
break;
case 9:
m_clock_factor = data;
break;
case 0xa:
m_forced_test = data;
break;
case 0xb:
m_control2 = data;
break;
case 0xc:
m_control3 = data;
break;
case 0xd:
m_control4 = data;
break;
case 0xe:
if (m_control2 & CR2_FEATURES_ENABLE)
{
m_dma_size &= 0xffff;
m_dma_size |= (data<<16);
m_chipid_available = false;
m_chipid_lock = true;
}
break;
case 0xf:
m_data_alignment = data;
break;
}
}
void ncr539x_device::exec_fifo()
{
int length, phase;
send_command(&m_fifo[0], 12);
length = get_length();
phase = get_phase();
#if VERBOSE
printf("Command executed (id %d), new phase %d, length %x\n", m_last_id, phase, length);
#endif
m_buffer_offset = m_buffer_size;
m_buffer_remaining = 0;
m_total_data = length;
m_status &= ~7; // clear bus phases
m_status |= (phase & 7); // set the phase reported by the device
}
void ncr539x_device::check_fifo_executable()
{
if (get_cmd_len(m_fifo[0]) == m_fifo_ptr)
{
exec_fifo();
}
}
void ncr539x_device::fifo_write(uint8_t data)
{
int phase = (m_status & 7);
if (phase != SCSI_PHASE_DATAOUT)
{
#if VERBOSE
printf("539x: Write %02x @ FIFO[%x]\n", data, m_fifo_ptr);
#endif
m_fifo[m_fifo_ptr++] = data;
update_fifo_internal_state(m_fifo_ptr);
if (m_selected)
{
check_fifo_executable();
}
}
else // phase is DATAOUT
{
m_buffer[m_buffer_offset++] = data;
m_xfer_count--;
m_total_data--;
#if VERBOSE
printf("539x: Write %02x @ buffer[%x], xfer_count %x, total %x\n", data, m_buffer_offset-1, m_xfer_count, m_total_data);
#endif
// default to flushing our entire buffer
int flush_size = m_buffer_size;
// if the actual size is less than the buffer size, flush that instead
if (m_dma_size < m_buffer_size)
{
flush_size = m_dma_size;
}
if ((m_buffer_offset == flush_size) || (m_xfer_count == 0))
{
#if VERBOSE
printf("Flushing buffer to device, %x bytes left in buffer (%x total)\n", m_xfer_count, m_total_data);
#endif
write_data(m_buffer, flush_size);
m_buffer_offset = 0;
// need a service request here too
m_irq_status = IRQ_STATUS_SERVICE_REQUEST;
m_status &= 7;
m_status |= MAIN_STATUS_INTERRUPT;
m_out_irq_cb(ASSERT_LINE);
}
if ((m_xfer_count == 0) && (m_total_data == 0))
{
#if VERBOSE
printf("End of write, asserting service request\n");
#endif
m_buffer_offset = 0;
m_irq_status = IRQ_STATUS_SERVICE_REQUEST;
m_status = MAIN_STATUS_INTERRUPT | SCSI_PHASE_STATUS;
m_out_irq_cb(ASSERT_LINE);
}
}
}
void ncr539x_device::update_fifo_internal_state(int bytes)
{
if (bytes >= 0x1f)
{
m_fifo_internal_state |= 0x1f;
}
else
{
m_fifo_internal_state &= ~0x1f;
m_fifo_internal_state |= (bytes & 0x1f);
}
}