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Initiator and target synchronous transfer – Avago Technologies LSI53C895A User Manual

Page 323

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SCSI Timing Diagrams

6-63

Figure 6.39 Initiator and Target Synchronous Transfer

Table 6.50

Ultra2 SCSI Transfers 40.0 Mbytes (8-Bit Transfers) or 80.0 Mbytes
(16-Bit Transfers) Quadrupled 40 MHz Clock

1, 2

1. Transfer period bits (bits [7:5] in the

SCSI Transfer (SXFER)

register) are set to zero and the Extra

Clock Cycle of Data Setup bit (bit 7 in

SCSI Control One (SCNTL1)

) is set.

2. During Ultra2 SCSI transfers, the value of the Extend REQ/ACK Filtering bit (

SCSI Test Two

(STEST2)

, bit 1) has no effect.

Symbol

Parameter

Min

Max

Unit

t

1

Send SREQ/ or SACK/ assertion pulse width

8

ns

t

2

Send SREQ/ or SACK/ deassertion pulse width

8

ns

t

1

Receive SREQ/ or SACK/ assertion pulse width

6.5

ns

t

2

Receive SREQ/ or SACK/ deassertion pulse width

6.5

ns

t

3

Send data setup to SREQ/ or SACK/ asserted

9.5

ns

t

4

Send data hold from SREQ/ or SACK/ asserted

9.5

ns

t

5

Receive data setup to SREQ/ or SACK/ asserted

4.5

ns

t

6

Receive data hold from SREQ/ or SACK/ asserted

4.5

ns

SREQ/

or SACK/

Send Data

SD[15:0]/, SDP[1:0]/

Receive Data

SD[15:0]/,

SDP[1:0]/

t

3

t

4

t

1

t

2

t

5

t

6

n

n + 1

Valid n

Valid n + 1

Valid n

Valid n + 1