LXT974/LXT975 — Fast Ethernet 10/100 Quad Transceivers
Figure 31. MII - 10BASE-T Transmit Timing
TX_CLK
t
1
t2
TXD,
TX_EN,
TX_ER
t
3
t4
CRS
TPO
t
5
Table 36. MII - 10BASE-T Transmit Timing Parameters
1
Parameter
Sym
Min
Typ
Max
Units
TXD, TX_EN, TX_ER setup to TX_CLK High
TXD, TX_EN, TX_ER hold from TX_CLK High
TX_EN sampled to CRS asserted
t1
t2
t3
t4
t5
10
0
–
-1
2
–
–
4
–
–
ns
ns
–
BT
BT
BT
TX_EN sampled to CRS de-asserted
TX_EN sampled to TPO out (Tx latency)
–
8-11
3 - 5
–
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Figure 32. 10BASE-T SQE (Heartbeat) Timing
TX_CLK
TX_EN
t
1
t2
COL
Table 37. 10BASE-T SQE (Heartbeat) Timing Parameters
1
Parameter
Sym
Min
Typ
Max
Units
COL (SQE) delay after TX_EN off
COL (SQE) pulse duration
t1
t2
0.65
.5
1.0
1.0
1.6
1.5
µs
µs
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
58
Datasheet
INTEL [ INTEL ]
