DP83256 datasheet(86/146 Pages) TI1

86 / 146 page

50 Registers (Continued)

541 CLOCK GENERATION MODULE REGISTER (CGMREG)

This register is used to enable or disable the 125 MHz ECL Transmit clock outputs These outputs are not required for use in a

standard FDDI board implementation and are disabled by default to reduce high frequency noise

These TXC outputs are included for support of alternate FDDI PMDs such as unshielded twisted pair copper cable

DO NOT WRITE TO RESERVED REGISTER BITS Writes to reserved register bits could prevent proper device operation

Therefore read the register first and then write it back with the non-reserved bits set to the desired value

ACCESS RULES

ADDRESS

READ

WRITE

3Bh

Always

RES

FLTREN

RES

TXCE

RES

Bit

Symbol

Description

D0-D2

RES

RESERVED BITS

DO NOT CHANGE THE VALUE OF THESE BITS Changes to reserved register bits could

prevent proper device operation

TXCE

TRANSMIT CLOCK ENABLE

When bit is set to 1 125 MHz ECL TXC outputs are enabled When this bit is

reset to 0 TXC outputs are disabled TXC outputs are disabled on reset

Note

TXC clocks are only available on the 160-pin DP83257 PLAYERa device

RES

RESERVED BITS

DO NOT CHANGE THE VALUE OF THESE BITS Changes to reserved register bits could

prevent proper device operation

FLTREN

FILTER ENABLE

When bit is set to 1 the internal loop filter node is connected to the LPFLTR pin for

diagnostic viewing This bit is reset to 0 by default which disconnects the filter node from the LPFLTR pin

Note

In normal operation this bit should be disabled (e0)

D6-D7

RES

RESERVED BITS

DO NOT CHANGE THE VALUE OF THESE BITS Changes to reserved register bits could

prevent proper device operation

DP83256 데이터시트(PDF) 86 Page - Texas Instruments

DP83256 데이터시트(HTML) 86 Page - Texas Instruments

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

데이터시트 다운로드

링크 URL