In the case of a SCSI data receive, if there is a byte in the SCSI Wide Residue (SWIDE) register then this address will point to the location where that byte must be stored. The SWIDE byte must be manually written to memory and this address must be incremented prior to updating any scatter/gather entry.

In the case of a SCSI data receive, if there is not a byte in the SWIDE register then this address will be the next location that should be written to when this I/O restarts. No manual flushing will be necessary.

In the case of a SCSI data send, all data sent to the SCSI bus will be accounted for and any data left in the part will be ignored and will be automatically cleared from the FIFOs.

Registers: 0xD0–0xD3

Entry Storage Address (ESA)

Read/Write

31

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ESA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

 

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

 

0

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This register's value depends on the type of BMOV being executed. The

 

 

 

 

 

 

 

three types of BMOVs are listed below.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ESA

 

 

 

Entry Storage Address

 

 

 

 

 

 

 

 

 

[31:0]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This register's value depends on the type of BMOV being

 

 

 

 

 

 

 

 

 

 

 

 

 

executed. The three types of BMOVs are listed below.

 

 

Direct BMOV:In the case of a direct BMOV, this register will contain the address the BMOV was fetched from when the phase mismatch occurred.

Indirect BMOV: In the case of an indirect BMOV, this register will contain the address the BMOV was fetched from when the phase mismatch occurred.

Table Indirect BMOV: In the case of a table indirect BMOV, this register will contain the address of the table indirect entry being used when the phase mismatch occurred.

4-106Registers

Page 198
Image 198
LSI 53C875A technical manual Registers 0xD0-0xD3, Entry Storage Address ESA Read/Write, Esa, Entry Storage Address 310