S/UNI®-JET Data Sheet
Released
For G.751 E3 streams, the National Use bit is sourced by the TDPR block if TNETOP and the
NATUSE bit (from the E3 TRAN Configuration Register 341H) are both logic zero. If either
TNETOP or NATUSE is logic one, the National Use bit will be sourced from the NATUSE
register bit in Register 341H.
If the S/UNI-JET is configured for DS3 or J2 operation, TNETOP has no effect. The DS3 C-
bit Parity and J2 datalink is inserted into the DS3 or J2 stream through the internal HDLC
transmitter TDPR.
The TOH and TOHINS input pins can be used to overwrite the values of these overhead bits
in the transmit stream.
LOSEN
The LOSEN bit enables the receive LOS indication to automatically generate a FERF
indication in the transmit stream. This bit operates regardless of framer selected (DS3, E3, or
J2). When LOSEN is logic one, assertion of the LOS indication by the framer causes a FERF
(RAI in G.751 or J2 mode) to be transmitted by TRAN for the duration of the LOS assertion.
When LOSEN is logic zero, assertion of the LOS indication does not cause transmission of a
FERF/RAI.
Note: For the RAI to be automatically transmitted when in J2 format, the FEAC[5:0] bits in
the XBOC Code Register must all be set to logic one. If the XBOC FEAC code is to be
transmitted in J2 mode, LOSEN, OOFEN, AISEN, and LCDEN should all be set to logic
zero.
OOFEN
The OOFEN bit enables the receive OOF indication to automatically generate a FERF
indication (RAI in G.751 or J2 mode) in the transmit stream. This bit operates when the E3 or
J2 framer is selected or when the DS3 framer is selected and the RBLEN bit is logic zero.
When OOFEN is logic one, assertion of the OOF indication by the framer causes a
FERF/RAI to be transmitted by TRAN for the duration of the OOF assertion. When OOFEN
is logic zero, assertion of the OOF indication does not cause transmission of a FERF/RAI.
Note: For the RAI to be automatically transmitted when in J2 format, the FEAC[5:0] bits in
the XBOC Code Register must all be set to logic one. If the XBOC FEAC code is to be
transmitted in J2 mode, LOSEN, OOFEN, AISEN, and LCDEN should all be set to logic
zero.
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
92
PMC [ PMC-SIERRA, INC ]
