LAN8741AI-EN datasheet(92/106 Pages) MICROCHIP

92 / 106 page

LAN8741A/LAN8741Ai

DS00001988A-page 92

 2013-2015 Microchip Technology Inc.

5.6.4

RMII INTERFACE TIMING

This section specifies the RMII interface transmit and receive timing.

Note 1: Timing was designed for system load between 10 pF and 25 pF.

Note:

The CRS_DV pin performs both carrier sense and data valid functions. CRS_DV is asserted asynchro-

nously on detection of carrier due to the criteria relevant to the operating mode. If the PHY has additional

bits to be presented on RXD[1:0] following the initial deassertion of CRS_DV, then the device will assert

CRS_DV on cycles of REF_CLK which present the second di-bit of each nibble and deassert CRS_DV on

cycles of REF_CLK which present the first di-bit of a nibble. For additional information, refer to the RMII

specification.

FIGURE 5-6:

RMII TIMING

TABLE 5-12:

RMII TIMING VALUES

Symbol

Description

Min.

Typ.

Max.

Unit

Note

tclkp

CLKIN period

tclkh

CLKIN high time

tclkp * 0.35

tclkp * 0.65

tclkl

CLKIN low time

tclkp * 0.35

tclkp * 0.65

toval

RXD[1:0], RXER, CRS_DV output

valid from rising edge of CLKIN

15.0

(see Note 1)

toinvld

RXD[1:0], RXER, CRS_DV output

invalid from rising edge of CLKIN

3.0

(see Note 1)

tsu

TXD[1:0], TXEN setup time to ris-

ing edge of CLKIN

4.0

(see Note 1)

tihold

TXD[1:0], TXEN input hold time

after rising edge of CLKIN

1.5

(see Note 1)

tclkh

tclkl

tclkp

toval

toinvld

toval

toinvld

tsu tihold

tihold

tsu

tihold

CLKIN

(REF_CLK)

(INPUT)

RXD[1:0], RXER

(OUTPUTS)

CRS_DV

(OUTPUT)

TXD[1:0]

(INPUTS)

TXEN

(INPUT)

LAN8741Ai-EN Datasheet(PDF) 92 Page - Microchip Technology

LAN8741Ai-EN Datasheet(HTML) 92 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL