am79c974 Advanced Micro Devices, am79c974 Datasheet - Page 98

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

AC SWITCHING CHARACTERISTICS
SCSI Interface
FastClk Disabled (Control Register Three (0CH) bit 3=0), See Figure 29
Notes:
1. For Synchronous data transmissions, the following condi-
FastClk Enabled (Control Register Three (0CH) bit 3=1), See Figure 29
Notes:
Clock Frequency Range for Fast Clk enabled.
98
No.
No.
tions must be true:
2t CP + t PWL ≥ 97.92 ns
2t CP + t PWH ≥ 97.92 ns
= 20 MHz to 40 MHz for Asynchronous Transmission
= 20 MHz to 40 MHz for Synchronous Transmission
3A
1
2
3
4
5
6
1
2
4
5
6
AMD
Parameter
Parameter
Symbol
Symbol
tRISE*
tFALL*
tRISE*
tFALL*
tPWH
tPWL
tPWH
tPWL
tCP
tCP
tL
tL
1
1
Parameter Description
Clock Pulse Width Low
Clock Period (1
Synchronization Latency
Clock Pulse Width High
Clock Rise Time
Clock Fall Time
Parameter Description
Clock Pulse Width Low
Clock Period (1
Synchronization Latency
Clock Pulse Width High
Clock Rise Time
Clock Fall Time
Clock Frequency)
Clock Frequency)
P R E L I M I N A R Y
Am79C974
Clock Frequency Range for Fast Clk disabled.
*
*
= 10 MHz to 25 MHz for Asynchronous Transmission
= 12 MHz to 25 MHz for Synchronous Transmission
These parameters are not 100% tested, but are evalu-
ated at initial characterization and at any time the design
is modified where these parameters may be affected.
These parameters are not 100% tested, but are evalu-
ated at initial characterization and at any time the design
is modified where these parameters may be affected.
Test Conditions
Test Conditions
over 2 V p-p
over 2 V p-p
over 2 V p-p
over 2 V p-p
0.4 tCP
0.4 tCP
14.58
54.58
14.58
54.58
Min
Min
40
25
1
1
1
1
0.65 tCP
0.65 tCP
tPWL + tCP
0.6 tCP
0.6 tCP
2 tCP
Max
Max
100
50
4
4
4
4
Unit
V/ns
V/ns
Unit
V/ns
V/ns
ns
ns
ns
ns
ns
ns
ns
ns