Data underflow – reading the SCSI FIFO when no data was present.

Data overflow – writing to the SCSI FIFO while it is full.

Offset underflow – receiving a SACK/ pulse in target mode before the corresponding SREQ/ is sent.

Offset overflow – receiving an SREQ/ pulse in the initiator mode, and exceeding the maximum offset (defined by the MO[3:0] bits in the SCSI Transfer (SXFER) register).

A phase change in the initiator mode, with an outstanding SREQ/SACK offset.

Residual data in SCSI FIFO – starting a transfer other than synchronous data receive with data left in the SCSI synchronous receive FIFO.

UDC

Unexpected Disconnect

2

 

This bit controls whether an interrupt occurs in the case

 

of an unexpected disconnect. This condition only occurs

 

in initiator mode. It happens when the target to which the

 

LSI53C810A is connected disconnects from the SCSI

 

 

bus unexpectedly. See the SCSI Disconnect Unexpected

 

bit in the SCSI Control Two (SCNTL2) register for more

 

information on expected versus unexpected disconnects.

 

Any disconnect in low level mode causes this condition.

RST

SCSI Reset Condition

1

 

This bit controls whether an interrupt occurs when the

 

 

SRST/ signal is asserted by the LSI53C810A or any

 

 

other SCSI device. Note that this condition is

 

 

edge-triggered, so that multiple interrupts cannot occur

 

 

because of a single SRST/ pulse.

 

PAR

SCSI Parity Error

0

 

This bit controls whether an interrupt occurs when the

 

 

LSI53C810A detects a parity error while receiving or

 

sending SCSI data. See the Disable Halt on Parity Error or SATN/ Condition bits in the SCSI Control One (SCNTL1) register for more information on when this condition is actually raised.

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LSI 53C810A technical manual Udc, Unexpected Disconnect, Scsi Reset Condition, Par