XRT86VL38
PRELIMINARY
xr
OCTAL T1/E1/J1 FRAMER/LIU COMBO
REV. P1.0.6
313
4.8
T1/E1 Time Slot Substitution and Control
The time slots within PCM data are reserved for carrying individual DS-0’s. However, the framer block
(transmit or receive paths) can substitute the payload with various code definitions. Each time slot can be
independently programmed to carry normal PCM data or a variety of user codes. In E1 mode, the user can
substitute the transmit time slots 0 and 16, although signaling and Frame Sync cannot be maintained. The
following options for time slot substitution are available:
•
Unchanged
•
Invert all bits
•
Invert even bits
•
Invert odd bits
•
Programmable User Code
•
Busy 0xFF
•
Vacant 0xD5
•
Busy TS, Busy 00
•
A-Law,
µ
-Law
•
Invert the MSB bit
•
Invert all bits except the MSB bit
•
PRBS
•
D/E Channel (or Fractional Input)
F
IGURE
20. T1/E1 T
IME
S
LOT
S
UBSTITUTION
AND
C
ONTROL
F
TS
n
- TS
n+m
Substitution
TxSER
TxSERclk
TxSYNC
TxMSYNC
PCM Data
PCM Data