SN75C091A Datasheet, PDF (91/106 Pages) Texas Instruments – SCSI Bus Controller

7.45 timing requirements over recommended operating free-air temperature
and supply voltage ranges
PARAMETER
TEST
CONDITIONS
MIN MAX UNIT
td1 Delay time, REQ low to ACK low
td2 Delay time, REQ high to ACK high
0
ns
See Figure 7–25
0
ns
7.46 timing characteristics over recommended operating free-air temperature
and supply voltage ranges
PARAMETER
TEST
CONDITIONS
MIN MAX UNIT
td3
Delay time, MSG, C/D valid and I/O low to SDP, SD(0:7)
active
800
ns
td4 Delay time, ACK high to MSG, C/D invalid and I/O high
200
ns
td5 td5 Delay time, SDP, SD(0:7) valid to REQ low
CL = 50 pF,
55
See Figure 7–25
ns
td6 Delay time, REQ high to SDP, SD(0:7) invalid
0
ns
tPLH Propagation delay, low to high, ACK low to REQ high
5
ns
tPHL tPHL Propagation delay, ACK high to REQ low
5
ns
MSG
C/D
Valid
Valid
I/O
REQ
td3
td1
tPLH
td4
td2
tPHL
ACK
SDP, SD(0:7)
td6
td5
Valid
Figure 7–25. SCSI Bus Asynchronous Information Transfer In (Target)
(TARGET TO INITIATOR)
7–26