Datasheet

9.0 Electrical Specifications (Continued)
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9.9 Loopback Timing
Note: Due to the nature of the descrambler function, all 100BASE-X 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-X timing specified is based on device delays after the initial 550µs “dead-time”.
Note: During loopback (all modes) both the TPTD± or FXTD/AUITD± outputs remain inactive by default.
Parameter Description Notes Min Typ Max Units
T9.23.1 TX_EN to RX_DV Loopback 100 Mb/s 240 ns
10 Mb/s Serial mode 650 ns
10 Mb/s Nibble mode 2 µs
TX_CLK
TX_EN
TXD[3:0]
CRS
RX_CLK
RXD[3:0]
RX_DV
T9.23.1