IAR-KSK-IMX25 Freescale Semiconductor, IAR-KSK-IMX25 Datasheet - Page 89

• Manufacturer Part Number: IAR-KSK-IMX25
• Description: KIT DEVELOPMENT I.MX257, ARM926
• Manufacturer: Freescale Semiconductor
• Series: i.MX25r
• Type: MCUr

Specifications of IAR-KSK-IMX25

• Contents: Board, Cables, CD, Debugger, Power Supply
• Processor To Be Evaluated: I.MX257
• Processor Series: i.MX25
• Data Bus Width: 16 bit
• Interface Type: UART, JTAG, USB, Ethernet, SD/MMC
• Core: ARM926EJ-S
• Silicon Manufacturer: Freescale
• Core Architecture: ARM
• Core Sub-architecture: ARM9
• Silicon Core Number: I.MX2
• Silicon Family Name: I.MX25
• Mcu Supported Families: I.MX25
• For Use With/related Products: i.MX25
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.7.9.3
In RMII mode, FEC_TX_CLK is used as the REF_CLK, which is a 50 MHz ± 50 ppm continuous
reference clock. FEC_RX_DV is used as the CRS_DV in RMII. Other signals under RMII mode include
FEC_TX_EN, FEC_TXD[1:0], FEC_RXD[1:0] and FEC_RX_ER.
Figure 59
figure.
Freescale Semiconductor
M16
M17
M18
M19
M20
M21
ID
FEC_TXD[1:0] (output)
FEC_TX_EN
FEC_RXD[1:0]
FEC_RX_ER
REF_CLK(FEC_TX_CLK) pulse width high
REF_CLK(FEC_TX_CLK) pulse width low
REF_CLK to FEC_TXD[1:0], FEC_TX_EN invalid
REF_CLK to FEC_TXD[1:0], FEC_TX_EN valid
FEC_RXD[1:0], CRS_DV(FEC_RX_DV), FEC_RX_ER to REF_CLK setup
REF_CLK to FEC_RXD[1:0], FEC_RX_DV, FEC_RX_ER hold
REF_CLK (input)
shows RMII mode timings.
CRS_DV (input)
RMII Mode Timing
i.MX25 Applications Processor for Consumer and Industrial Products, Rev. 8
Figure 59. RMII Mode Signal Timing Diagram
Characteristic
Table 66
Table 66. RMII Signal Timing
M20
M18
describes the timing parameters (M16–M21) shown in the
M21
M19
M16
M17
35%
35%
Min.
—
3
2
2
Max.
65%
65%
12
—
—
—
REF_CLK period
REF_CLK period
Unit
ns
ns
ns
ns
89