
MPC8641 and MPC8641D Integrated Host Processor Hardware Specifications, Rev. 0
Freescale Semiconductor
41
Ethernet: Enhanced Three-Speed Ethernet (eTSEC), MII Management
Figure 20 shows the RMII transmit AC timing diagram.
Figure 20. RMII Transmit AC Timing Diagram
8.2.7.2
RMII Receive AC Timing Specifications
REF_CLK to RMII data TXD[1:0], TX_EN delay
tRMTDX
1.0
—
10.0
ns
Note:
1. The symbols used for timing specifications herein follow the pattern of t(first two letters of functional block)(signal)(state)
(reference)(state) for inputs and t(first two letters of functional block)(reference)(state)(signal)(state) for outputs. For example,
tMTKHDX symbolizes MII transmit timing (MT) for the time tMTX clock reference (K) going high (H) until data outputs
(D) are invalid (X). Note that, in general, the clock reference symbol representation is based on two to three letters
representing the clock of a particular functional. For example, the subscript of tMTX represents the MII(M) transmit
(TX) clock. For rise and fall times, the latter convention is used with the appropriate letter: R (rise) or F (fall).
Table 37. RMII Receive AC Timing Specifications
At recommended operating conditions with L/TVDD of 3.3 V ± 5%.
Parameter/Condition
Symbol 1
Min
Typ
Max
Unit
REF_CLK clock period
tRMR
15.0
20.0
25.0
ns
REF_CLK duty cycle
tRMRH/tRMR
35
50
65
%
REF_CLK peak-to-peak jitter
tRMRJ
—
250
ps
Rise time REF_CLK (20%–80%)
tRMRR
1.0
—
2.0
ns
Fall time REF_CLK (80%–20%)
tRMRF
1.0
—
2.0
ns
RXD[1:0], CRS_DV, RX_ER setup time to REF_CLK
rising edge
tRMRDV
4.0
—
ns
Table 36. RMII Transmit AC Timing Specifications (continued)
At recommended operating conditions with L/TVDD of 3.3 V ± 5%.
Parameter/Condition
Symbol 1
Min
Typ
Max
Unit
REF_CLK
TXD[1:0]
tRMTDX
tRMT
tRMTH
tRMTR
tRMTF
TX_EN
TX_ER