ICS1892 Datasheet, PDF (141/148 Pages) Integrated Circuit Systems – 10Base-T/100Base-TX Integrated PHYceiver

ICS1892
Chapter 10 DC and AC Operating Conditions
10.5.18 10Base-T: Heartbeat Timing (SQE)
Table 10-25 lists the significant time periods for the 10Base-T heartbeat (that is, the Signal Quality Error,
which consists of timings of signals on the TXEN, TXCLK, and COL pins). Figure 10-18 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 10-25. 10Base-T Heartbeat (SQE) Timing
Time
Period
Parameter
Conditions
t1 COL Heartbeat Assertion Delay from 10Base-T Half Duplex
TXEN De-Assertion
t2 COL Heartbeat Assertion Duration 10Base-T Half Duplex
Min.
–
–
Typ.
840
1000
Max. Units
1600 ns
1500 ns
Figure 10-18. 10Base-T Heartbeat (SQE) Timing Diagram
TXEN
TXCLK
COL
t1
t2
ICS1892, Rev. D, 2/26/01
© 2000-2001, Integrated Circuit Systems, Inc.
All rights reserved.
141
February 26, 2001