Table 2.2

SCSI Parity Control

 

 

 

EPC

AESP

Description

 

 

 

0

0

Does not check for parity errors. Parity is generated when sending

 

 

SCSI data. Asserts odd parity when sending SCSI data.

 

 

 

0

1

Does not check for parity errors. Parity is generated when sending

 

 

SCSI data. Asserts even parity when sending SCSI data.

 

 

 

1

0

Checks for odd parity on SCSI data received. Parity is generated

 

 

when sending SCSI data. Asserts odd parity when sending SCSI

 

 

data.

 

 

 

1

1

Checks for odd parity on SCSI data received. Parity is generated

 

 

when sending SCSI data. Asserts even parity when sending SCSI

 

 

data.

 

 

 

1.Key:

EPC = Enable Parity Checking (bit 3, SCSI Control Zero (SCNTL0)). ASEP = Assert SCSI Even Parity (bit 2, SCSI Control One (SCNTL1)).

Table 2.3

SCSI Parity Errors and Interrupts

 

 

 

DPH

PAR

Description

 

 

 

0

0

Halts when a parity error occurs in the target or initiator mode and

 

 

does not generate an interrupt.

 

 

 

0

1

Halts when a parity error occurs in the target mode and generates

 

 

an interrupt in target or initiator mode.

 

 

 

1

0

Does not halt in target mode when a parity error occurs until the

 

 

end of the transfer. An interrupt is not generated.

 

 

 

1

1

Does not halt in target mode when a parity error occurs until the

 

 

end of the transfer. An interrupt is generated.

 

 

 

Key:

DHP = Disable Halt on SATN/ or Parity Error (bit 5, SCSI Control One (SCNTL1). PAR = Parity Error (bit 0, SCSI Interrupt Enable Zero (SIEN0).

This table only applies when the Enable Parity Checking bit is set.

Parity Options

2-7

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LSI 53C810A technical manual Scsi Parity Control, Scsi Parity Errors and Interrupts