RMII_MHz_50_CLK
RMII_TXEN
RMII_TXD[1:0]
RMII_RXD[1:0]
RMII_CRS_DV
RMII_RXER
1
2
3
5
5
4
6
7
8
9
10
11
OMAP-L137
www.ti.com
SPRS563G – SEPTEMBER 2008 – REVISED JUNE 2014
Table 6-39. EMAC Control Module RAM
BYTE ADRESS
REGISTER DESCRIPTION
0x01E2 0000 - 0x01E2 1FFF
EMAC Local Buffer Descriptor Memory
Table 6-40. RMII Timing Requirements
No.
PARAMETER
MIN
TYP
MAX
UNIT
1
tc(REFCLK)
Cycle Time, RMII_MHZ_50_CLK
20
ns
2
tw(REFCLKH)
Pulse Width, RMII_MHZ_50_CLK High
7
13
ns
3
tw(REFCLKL)
Pulse Width, RMII_MHZ_50_CLK Low
7
13
ns
6
tsu(RXD-REFCLK)
Input Setup Time, RXD Valid before RMII_MHZ_50_CLK High
4
ns
7
th(REFCLK-RXD)
Input Hold Time, RXD Valid after RMII_MHZ_50_CLK High
2
ns
8
tsu(CRSDV-REFCLK)
Input Setup Time, CRSDV Valid before RMII_MHZ_50_CLK High
4
ns
9
th(REFCLK-CRSDV)
Input Hold Time, CRSDV Valid after RMII_MHZ_50_CLK High
2
ns
10
tsu(RXER-REFCLK)
Input Setup Time, RXER Valid before RMII_MHZ_50_CLK High
4
ns
11
th(REFCLKR-RXER)
Input Hold Time, RXER Valid after RMII_MHZ_50_CLK High
2
ns
Note:
Per the RMII industry specification, the RMII reference clock (RMII_MHZ_50_CLK) must have jitter
tolerance of 50 ppm or less.
Table 6-41. RMII Switching Characteristics
No.
PARAMETER
MIN
TYP
MAX
UNIT
4
td(REFCLK-TXD)
Output Delay Time, RMII_MHZ_50_CLK High to TXD Valid
2.5
13
ns
5
td(REFCLK-TXEN)
Output Delay Time, RMII_MHZ_50_CLK High to TXEN Valid
2.5
13
ns
Figure 6-30. RMII Timing Diagram
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