Texas Instruments AM1808 - Page 192

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
AM1808
SPRS653E –FEBRUARY 2010–REVISED MARCH 2014 www.ti.com
Table 6-102. Timing Requirements for EMAC RMII
1.3V, 1.2V, 1.1V
(1)
NO. UNIT
MIN TYP MAX
1 tc(REFCLK) Cycle Time, RMII_MHZ_50_CLK
(2)
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
(1) RMII is not supported at operating points below 1.1V nominal.
(2) Per the RMII industry specification, the RMII reference clock (RMII_MHZ_50_CLK) must have jitter tolerance of 50 ppm or less.
Table 6-103. Switching Characteristics Over Recommended Operating Conditions for EMAC RMII
1.3V, 1.2V, 1.1V
(1)
NO. PARAMETER UNIT
MIN TYP MAX
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
(1) RMII is not supported at operating points below 1.1V nominal.
Figure 6-49. RMII Timing Diagram
192 Peripheral Information and Electrical Specifications Copyright © 2010–2014, Texas Instruments Incorporated
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