8.2.23 100BASE-TX Signal Detect Timing
PMD Input Pair
T2.23.1
T2.23.2
SD+ internal
Parameter
T2.23.1
Description
Notes
Min
Typ Max Units
SD Internal Turn-on Time
SD Internal Turn-off Time
1
ms
T2.23.2
350
µs
Note: The signal amplitude on PMD Input Pair must be TP-PMD compliant.
8.2.24 100 Mb/s Internal Loopback Timing
TX_CLK
TX_EN
TXD[3:0]
CRS
T2.24.1
RX_CLK
RX_DV
RXD[3:0]
Parameter
Description
Notes
Min
Typ Max Units
240 ns
T2.24.1
TX_EN to RX_DV Loopback
100 Mb/s internal loopback mode
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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