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LSI 53C810A User Manual

Page 97

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OLF

SODL Full

5

This bit is set when

SCSI Output Data Latch (SODL)

contains data. The

SCSI Output Data Latch (SODL)

register is the interface between the DMA logic and the
SCSI bus. In synchronous mode, data is transferred from
the host bus to the

SCSI Output Data Latch (SODL)

register, and then to the SCSI Output Data Register
(SODR, a hidden buffer register which is not accessible)
before being sent to the SCSI bus. In asynchronous
mode, data is transferred from the host bus to the

SCSI

Output Data Latch (SODL)

register, and then to the SCSI

bus. The SODR buffer register is not used for
asynchronous transfers. It is possible to use this bit to
determine how many bytes reside in the chip when an
error occurs.

AIP

Arbitration in Progress

4

Arbitration in Progress (AIP = 1) indicates that the
LSI53C810A has detected a Bus Free condition, asserted
BSY, and asserted its SCSI ID onto the SCSI bus.

LOA

Lost Arbitration

3

When set, LOA indicates that the LSI53C810A has
detected a bus free condition, arbitrated for the SCSI bus,
and lost arbitration due to another SCSI device asserting
the SEL/ signal.

WOA

Won Arbitration

2

When set, WOA indicates that the LSI53C810A has
detected a Bus Free condition, arbitrated for the SCSI
bus and won arbitration. The arbitration mode selected in
the

SCSI Control Zero (SCNTL0)

register must be full

arbitration and selection for this bit to be set.

RST/

SCSI RST/ Signal

1

This bit reports the current status of the SCSI RST/
signal, and the SRST signal (bit 6) in the

Interrupt Status

(ISTAT)

register.

SDP/

SCSI SDP/ Parity Signal

0

This bit represents the active high current status of the
SCSI SDP/ parity signal.