MCIMX25 Motorola Semiconductor Products, MCIMX25 Datasheet - Page 85

• Manufacturer Part Number: MCIMX25
• Manufacturer: Motorola Semiconductor Products

1
3.6.9.2
The MDC frequency is designed to be equal to or less than 2.5 MHz to comply with the IEEE 802.3
standard MII specification. However the FEC can function correctly with a maximum MDC frequency of
15 MHz.
Figure 58
(M10—M15) shown in the figure.
Freescale Semiconductor
M10
M11
M12
M13
M14
M15
M9
FEC_COL has the same timing in 10-Mbit 7-wire interface mode.
1
ID
ID
FEC_MDIO (output)
FEC_MDC (output)
FEC_MDIO (input)
FEC_MDC falling edge to FEC_MDIO output invalid (min.
propagation delay)
FEC_MDC falling edge to FEC_MDIO output valid (max.
propagation delay)
FEC_MDIO (input) to FEC_MDC rising edge setup
FEC_MDIO (input) to FEC_MDC rising edge hold
FEC_MDC pulse width high
FEC_MDC pulse width low
FEC_CRS to FEC_COL minimum pulse width
shows MII asynchronous input timings.
MII Serial Management Channel Timing (FEC_MDIO and FEC_MDC)
i.MX25 Applications Processor for Consumer and Industrial Products, Rev. 2
Figure 58. MII Serial Management Channel Timing Diagram
Table 60. MII Asynchronous Inputs Signal Timing
Table 61. MII Serial Management Channel Timing
Characteristic
Characteristic
M12
M13
Table 61
M14
describes the timing parameters
Min.
1.5
Min.
40%
40%
M10
18
—
0
0
M11
M15
Max.
—
Max.
60%
60%
—
—
—
5
FEC_TX_CLK period
FEC_MDC period
FEC_MDC period
Unit
Unit
ns
ns
ns
ns
85