XRT5997 datasheet(21/37 Pages) EXAR

21 / 37 page

XRT5997

Rev. 1.0.0

TxPO S _x

TxNE G _x

TxClk _x

D ata

Bit

Pe riod

R Z P ulse is to be

applied in the first

half of the bit-period

N o pulse is to be applied

in the second half of the

bit period

N o A ctivity in TxClk Line

Figure 3. Illustration on how the Terminal Equipment should apply data to the “Transmit Section” of a

given Channel (within the XRT5997 Device), when operating in the “Clockless” Mode

Figure 3, indicates that when the user is operating a

channel in the “Clockless” Mode, then the correspond-

ing Terminal Equipment must do the following:

• Not apply a signal on the “TxClk_x” line.

• When applying a pulse (to either the TxPOS_x or

TxNEG_x input pin), apply an RZ pulse to the

appropriate input pin. This RZ pulse should only

have a width of one-half the bit-period. Addition,

the RZ pulse should occupy only the first half of

the bit-period. The TxPOS_x and TxNEG_x input

pins must be at 0V, during the second half of

every bit-period.

1.3

The Pulse Shaping Circuit

The purpose of the “Transmit Pulse Shaping” circuit is

to generate “Transmit Output” pulses that comply with

the ITU-T G.703 Pulse Template Requirements for E1

Applications.

XRT5997 Datasheet(PDF) 21 Page - Exar Corporation