41
LDM-144LR
M
ODE
B: RX-FIFO
This mode is used in applications where the G.703 co-directional 64-kbps side
recovers the clock from the modem link. This mode is used mainly when the
attached equipment has a G.703 co-directional interface, but no ability to
produce clock. The module has a 2-bit FIFO buffer for compensating for the
phase delay introduced by the G.703 device.
Figure A-4
illustrates the buffer
connection and the required application set-up. Other clock modes are
available in addition to the one shown in
Figure A-4
. The only restriction
is that the clock source must be MODEM B, or the clock should be recovered
by MODEM B from the DTE side.
Figure A-4. RX-FIFO Block Diagram.
TX
RX
RX Data
TX Data
TX
RX
INT or EXT
Clock Mode
EXT or INT
Clock Mode
(Dependent on the
attached network)
Modem A
Equipment
with G.703
interface
LINK
side
G.703
side
DTE
side
RCV Clock Mode
Modem B
Clock In
Clock
Out
IR-G.703 Module
Data
Clock
Recovery
Buffer
Clock
Recovery
