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Avago Technologies LSI53C1010R User Manual

Page 57

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SCSI Functional Description

2-27

Version 2.2

Copyright © 2000–2003 by LSI Logic Corporation. All rights reserved.

2.2.5.4 Register Considerations

The following is a summary of the registers and bits required to enable
Ultra160 SCSI on the LSI53C1010R device.

The PCI

Device ID

register value must be 0x21.

The PCI

Max_Lat (ML)

register contains a value of 0x12, indicating

it requires the bus every 4.5

µ

s.

The

SCSI Control Zero (SCNTL0)

register:

Bit 3, EPC (Enable Parity/CRC/AIP Checking) is set to enable
the CRC feature.

Bit 1, AAP (Assert SATN/ on Parity/CRC/AIP Error), is set in the
initiator mode to assert SATN/ automatically on the detection of
an error.

The

SCSI Control One (SCNTL1)

register:

Bit 5, DHP (Disable Halt on Parity/CRC/AIP Error or ATN)
(Target Only), is set in accordance with user requirements. When
bit 5 is cleared, a SCSI transfer halts if an error occurs. When
bit 5 is set, a SCSI transfer continues if an error occurs.

The

SCSI Control Three (SCNTL3)

register:

Bit 7 is now reserved. It was previously the Ultra Enable bit.

Bits [6:4], SCF[2:0] (Synchronous Clock Conversion Factor),
select the divisor of the SCLK frequency. The SCLK is divided
before its presentation to the synchronous SCSI control logic.

Bit 3, EWS (Enable Wide SCSI), is set to enable wide SCSI.
Ultra160 requires wide SCSI. Therefore, this bit must be set
during these transfers.

Bits [2:0] are reserved.

The

SCSI Transfer (SXFER)

register:

Bits [7:6] are reserved.

Bits [5:0], MO[5:0] (Max SCSI synchronous offset), are set for
the maximum offset.