
i.MX35 Applications Processors for Industrial and Consumer Products, Rev. 10
Freescale Semiconductor
63
Figure 41. MII Asynch Inputs Timing Diagram
4.9.8.5
MII Serial Management Channel Timing
Serial management channel timing is accomplished using FEC_MDIO and FEC_MDC. The FEC
functions correctly with a maximum MDC frequency of 2.5 MHz.
Table 51 lists MII serial management
channel timings.
The MDC frequency should be equal to or less than 2.5 MHz to be compliant with the IEEE 802.3 MII
specification. However the FEC can function correctly with a maximum MDC frequency of 15 MHz.
Table 51. MII Transmit Signal Timing
Num
Characteristic
Min.
Max.
Units
M10
FEC_MDC falling edge to FEC_MDIO output invalid (minimum
propagation delay)
0—
ns
M11
FEC_MDC falling edge to FEC_MDIO output valid (max.
propagation delay)
—5
ns
M12
FEC_MDIO (input) to FEC_MDC rising edge setup
18
—
ns
M13
FEC_MDIO (input) to FEC_MDC rising edge hold
0
—
ns
M14
FEC_MDC pulse width high
40%
60%
FEC_MDC period
M15
FEC_MDC pulse width low
40%
60%
FEC_MDC period
FEC_CRS, FEC_COL
M9