XRT7250 datasheet(437/463 Pages) EXAR

437 / 463 page

XRT7250

áç

DS3/E3 FRAMER IC

REV. 1.1.1

418

Interfacing the Receive Overhead Data Output In-

terface block to the Terminal Equipment (Method

Figure 206 illustrates how one should interface the

Receive Overhead Data Output Interface block to the

Terminal Equipment, when using Method 2 to sample

and process the overhead bits from the Inbound E3

data stream.

TABLE 89: LISTING AND DESCRIPTION OF THE PIN ASSOCIATED WITH THE RECEIVE OVERHEAD DATA OUTPUT

INTERFACE BLOCK (METHOD 2)

SIGNAL NAME

TYPE

DESCRIPTION

RxOH

Output

Receive Overhead Data Output pin:

The XRT7250 will output the overhead bits, within the incoming E3 frames, via this pin.

The Receive Overhead Output Interface will pulse the RxOHEnable output pin (for one RxOut-

Clk period) at approximately the middle of the RxOH bit period. The user is advised to design

the Terminal Equipment to latch the contents of the RxOH output pin, whenever the RxOHEn-

able output pin is sampled “High” on the falling edge of RxOutClk.

RxOHEnable

Output

Receive Overhead Data Output Enable - Output pin:

The XRT7250 will assert this output signal for one RxOutClk period when it is safe for the Ter-

minal Equipment to sample the data on the RxOH output pin.

RxOHFrame

Output

Receive Overhead Data Output Interface - Start of Frame Indicator:

The XRT7250 will drive this output pin “High” (for one period of the RxOH signal), whenever

the first overhead bit, within a given E3 frame is being driven onto the RxOH output pin.

RxOutClk

Output

Receive Section Output Clock Signal:

This clock signal is derived from the RxLineClk signal (from the LIU) for loop-timing applica-

tions, and the TxInClk signal (from a local oscillator) for local-timing applications. For E3 appli-

cations, this clock signal will operate at 34.368MHz.

The user is advised to design the Terminal Equipment to latch the contents of the RxOH pin,

anytime the RxOHEnable output signal is sampled “High” on the falling edge of this clock sig-

nal.

XRT7250 데이터시트(PDF) 437 Page - Exar Corporation

XRT7250 데이터시트(HTML) 437 Page - Exar Corporation

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