am79c974 Advanced Micro Devices, am79c974 Datasheet - Page 99

• Manufacturer Part Number: am79c974
• Description: Pcnettm-scsi Combination Ethernet And Scsi Controller For Pci Systems
• Manufacturer: Advanced Micro Devices

AC SWITCHING CHARACTERISTICS (continued)
SCSI Interface
* The minimum values have a wide range since they depend on the Synchronization latency. The synchronization latency, in
**These parameters are not 100% tested, but are evaluated at initial characterization and at any time the design is modified
Single Ended: Asynchronous Initiator Transmit, See Figure 30
Single Ended: Asynchronous Initiator Receive, See Figure 31
Normal SCSI: (Single Ended) Synchronous Initiator Transmit, See Figure 32
Fast SCSI: (Single Ended) Synchronous Initiator Transmit, See Figure 32
Synchronous Initiator Receive, See Figure 33
SCSI Bus Lines
turn, depends on the operating frequency of the device.
where these parameters may be affected.
No.
10
11
12
13
14
15
16
17
18
15
16
17
18
19
19
20
20
21
22
7
8
9
Parameter
Symbol
dVH/dt**
dVL/dt**
tRISE**
tFALL**
tPWH
tPWH
tPWH
tPWH
tPWL
tPWL
tPWL
tPWL
tPD
tPD
tPD
tPD
tPD
tS
tS
tH
tS
tH
tS
tH
tS
tH
Parameter Description
Data to ACK
REQ
REQ
REQ
REQ
REQ
Data to REQ
REQ
Data to REQ or ACK
Set Up Time
REQ or ACK Pulse Width Low
REQ or ACK Pulse Width High
ACK or REQ
Data to REQ or ACK
Set Up Time
REQ or ACK Pulse Width Low
REQ or ACK Pulse Width High
ACK or REQ
REQ Pulse Width Low
ACK Pulse Width Low
REQ Pulse Width High
ACK Pulse Width High
Data to REQ or ACK
Set Up Time
REQ or ACK
Rise Time, 10% to 90%
Fall Time, 10% to 90%
Slew Rate, Low to High
Slew Rate, High to Low
to Data Delay
to ACK
to ACK
to ACK
to Data Hold Time
to ACK
to Data Hold Time
Set Up Time
Set Up Time
to Data Hold Time
to Data Hold Time
Delay
Delay
Delay
Delay
P R E L I M I N A R Y
Am79C974
SCSI Termination
SCSI Termination
SCSI Termination
SCSI Termination
Test Conditions
+ 20 pF
+ 20 pF
+ 20 pF
+ 20 pF
100*
0.15
0.25
Min
55*
90*
90*
25*
30*
30*
35*
60
10
18
27
20
20
20
10
15
5
8
5
Max
0.50
0.80
50
50
50
50
20
12
AMD
Unit
V/ns
V/ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
99