DP83848YB_08 Datasheet, PDF (78/84 Pages) National Semiconductor (TI) – PHYTER® - Extreme Temperature Single Port 10/100 Mb/s Ethernet Physical Layer Transceiver

8.2.24 100 Mb/s Internal Loopback Timing
TX_CLK
TX_EN
TXD[3:0]
CRS
RX_CLK
T2.24.1
RX_DV
RXD[3:0]
Parameter
Description
Notes
T2.24.1
TX_EN to RX_DV Loopback 100 Mb/s internal loopback mode
Min Typ Max Units
240 ns
Note1: Due to the nature of the descrambler function, all 100BASE-TX Loopback modes will cause an initial “dead-time”
of up to 550 µs during which time no data will be present at the receive MII outputs. The 100BASE-TX timing specified is
based on device delays after the initial 550µs “dead-time”.
Note2: Measurement is made from the first rising edge of TX_CLK after assertion of TX_EN.
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