LXT972 Level One, LXT972 Datasheet - Page 40

• Manufacturer Part Number: LXT972
• Description: 3.3V Dual-Speed Fast Ethernet Transceiver Datasheet
• Manufacturer: Level One

LXT972 3.3V Dual-Speed Fast Ethernet Transceiver
Timing Diagrams
Figure 23: 100BASE-TX Receive Timing - 4B Mode
Table 25: 100BASE-TX Receive Timing Parameters - 4B Mode
40
RXD<3:0>, RX_DV, RX_ER setup
to RX_CLK High
RXD<3:0>, RX_DV, RX_ER hold
from RX_CLK High
CRS asserted to RXD<3:0>, RX_DV
Receive start of “J” to CRS asserted
Receive start of “T” to CRS de-asserted
Receive start of “J” to COL asserted
Receive start of “T” to COL de-asserted
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. BT is the duration of one bit as transferred to and from the MAC and is the reciprocal of the bit rate. 100BASE-T bit time = 10
Parameter
R X D < 3 : 0 >
R X _ C L K
R X _ D V
C R S
C O L
TPI
0ns
t4
t6
Sym
t1
t2
t3
t4
t5
t6
t7
Min
10
10
12
10
16
17
3
t3
Typ
–
–
–
–
–
–
–
1
250ns
Max
16
17
22
20
t5
t7
–
–
5
t1
t2
Units
BT
BT
BT
BT
BT
ns
ns
2
Test Conditions
-8
–
–
–
–
–
–
–
s or 10 ns.