am79c974 Advanced Micro Devices, am79c974 Datasheet - Page 97

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

AC SWITCHING CHARACTERISTICS
Attachment Unit Interface
Notes:
1. DI pulses narrower than t PWODI (min) will be rejected; pulses wider than t PWODI (max) will turn internal DI carrier sense on.
2. DI pulses narrower than t PWKDI (min) will maintain internal DI carrier sense on; pulses wider than t PWKDI (max) will turn internal
3. CI pulses narrower than t PWOCI (min) will be rejected; pulses wider than t PWOCI (max) will turn internal CI carrier sense on.
4. CI pulses narrower than t PWKCI (min) will maintain internal CI carrier sense on; pulses wider than t PWKCI (max) will turn internal
AUI Port
Internal MENDEC Clock Timing
Parameter
Symbol
DI carrier sense off.
CI carrier sense off.
tDOETD
tPWODI
tPWKDI
tPWOCI
tPWKCI
tDORM
tDOTR
tDOTF
tx1H
tx1R
tx1L
tx1F
tx1
Parameter Description
DO+, DO– Rise Time (10% to 90%)
DO+, DO– Fall Time (10% to 90%)
DO+, DO– Rise and Fall Time Mismatch
DO End of Transmission
DI Pulse Width Accept/Reject Threshold
DI Pulse Width Maintain/Turn-Off
Threshold
CI Pulse Width Accepth/Reject Threshold
CI Pulse Width Maintain/Turn-Off
Threshold
XTAL1 Period
XTAL1 HIGH Pulse Width
XTAL1 LOW Pulse Width
XTAL1 Rise Time
XTAL1 Fall Time
P R E L I M I N A R Y
Am79C974
Test Conditions
|VIN| > |VASQ| (Note 1)
|VIN| > |VASQ| (Note 2)
|VIN| > |VASQ| (Note 3)
|VIN| > |VASQ| (Note 4)
VIN = External Clock
VIN = External Clock
VIN = External Clock
VIN = External Clock
VIN = External Clock
49.995
Min
200
136
2.5
2.5
15
10
90
20
20
50.001
Max
375
200
160
5.0
5.0
1.0
45
26
5
5
AMD
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
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