mpc5553 Freescale Semiconductor, Inc, mpc5553 Datasheet - Page 46

• Manufacturer Part Number: mpc5553
• Description: Mpc5553 High Performance Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Electrical Characteristics
3.14
Media Independent Interface (MII) Fast Ethernet Controller (FEC) signals use transistor-to-transistor logic
(TTL) signal levels compatible with devices operating at 3.3 V. The timing specifications for the MII FEC
signals are independent of the system clock frequency (part speed designation).
3.14.1
The receive functions correctly up to an FEC_RX_CLK maximum frequency of 25 MHz plus one percent.
There is no minimum frequency requirement. The processor clock frequency must exceed four times the
FEC_RX_CLK frequency.
Table 28
Figure 29
46
Spec
1
2
3
4
FEC_RXD[3:0] (inputs)
FEC_RX_CLK (input)
FEC_RXD[3:0], FEC_RX_DV, FEC_RX_ER to FEC_RX_CLK setup
FEC_RX_CLK to FEC_RXD[3:0], FEC_RX_DV, FEC_RX_ER hold
FEC_RX_CLK pulse-width high
FEC_RX_CLK pulse-width low
lists MII FEC receive channel timings.
Fast Ethernet AC Timing Specifications
shows MII FEC receive signal timings listed in
MII FEC Receive Signal Timing
FEC_RXD[3:0], FEC_RX_DV, FEC_RX_ER, and FEC_RX_CLK
FEC_RX_ER
FEC_RX_DV
Figure 29. MII FEC Receive Signal Timing Diagram
Characteristic
MPC5553 Microcontroller Data Sheet, Rev. 2.0
Table 28. MII FEC Receive Signal Timing
M1
M2
M3
Table
28.
M4
35%
35%
Min
5
5
65%
65%
Max
—
—
Freescale Semiconductor
FEC_RX_CLK period
FEC_RX_CLK period
Unit
ns
ns