ICS1893 Datasheet, PDF (145/152 Pages) Integrated Circuit Systems – 3.3-V 10Base-T/100Base-TX Integrated PHYceiver™

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Chapter 10 DC and AC Operating Conditions
10.5.19 10Base-T: Heartbeat Timing (SQE)
Table 10-26 lists the significant time periods for the 10Base-T heartbeat (that is, the Signal Quality Error).
The time periods consist of timings of signals on the following pins:
• TXEN
• TXCLK
• COL
Figure 10-20 shows the timing diagram for the time periods.
Note:
1. For more information on 10Base-T SQE operations, see Section 7.5.10, “10Base-T Operation: SQE
Test”.
2. In 10Base-T mode, one bit time = 100 ns.
Table 10-26. 10Base-T Heartbeat (SQE) Timing
Time
Period
Parameter
t1 COL Heartbeat Assertion Delay from
TXEN De-Assertion
t2 COL Heartbeat Assertion Duration
Conditions
Min. Typ.
10Base-T Half Duplex – 850
10Base-T Half Duplex – 1000
Max. Units
1500 ns
1500 ns
Figure 10-20. 10Base-T Heartbeat (SQE) Timing Diagram
TXEN
TXCLK
COL
t1
t2
ICS1893 Rev C 6/6/00
Copyright © 2000, Integrated Circuit Systems, Inc.
All rights reserved.
145
June, 2000