DP83848YB_08 NSC [National Semiconductor], DP83848YB_08 Datasheet - Page 81

• Manufacturer Part Number: DP83848YB_08
• Manufacturer: NSC [National Semiconductor]

8.2.27 RMII Receive Timing
Note: Per the RMII Specification, output delays assume a 25pF load.
Note: CRS_DV is asserted asynchronously in order to minimize latency of control signals through the why. CRS_DV may
toggle synchronously at the end of the packet to indicate CRS deassertion.
Note: RX_DV is synchronous to X1. While not part of the RMII specification, this signal is provided to simplify recovery of
receive data.
T2.27.1
T2.27.2
T2.27.3
T2.27.4
T2.27.5
Parameter
PMD Input Pair
RX_DV
CRS_DV
RXD[1:0]
RX_ER
X1
X1 Clock Period
RXD[1:0], CRS_DV, RX_DV
and RX_ER output delay from
X1 rising
CRS ON delay
CRS OFF delay
RXD[1:0] and RX_ER latency
T2.27.3
IDLE
Description
(J/K)
T2.27.2
Data
50 MHz Reference Clock
From JK symbol on PMD Receive Pair to
initial assertion of CRS_DV
From TR symbol on PMD Receive Pair to
initial deassertion of CRS_DV
From symbol on Receive Pair. Elasticity
buffer set to default value (01)
T2.27.5
81
T2.27.2
Notes
T2.27.1
(TR)
T2.27.4
T2.27.2
Data
Min
2
T2.27.2
18.5
Typ
20
27
38
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Max
14
Units
bits
bits
bits
ns
ns