S/UNI®-JET Data Sheet
Released
Figure 54 Transmit G.751 E3 Overhead
G.751 Frame Period
...
TOHFP
...
...
TOHCLK
RAI Nat C11C21 C31
C12 C22 C32
C13 C23 C33
J1 J2 J3
RAI
C41
C42
C43
J4
TOH
...
TOHINS
30 cycles
The Transmit G.751 E3 Overhead diagram (Figure 54) shows the insertion of G.751 overhead bits
RAI, the National Use Bit, and the stuff indication and opportunity bits using the TOH input,
along with the overhead insertion enable input, TOHINS. The TOHFP output is set to logic one
once per G.751 E3 frame period (during the RAI bit position). In Figure 54, the data sampled on
TOH during the RAI, National Use, or stuff bit positions while TOHINS is logic one is inserted
into the G.751 E3 overhead bits in the transmit stream.
The PYLD&JUST bit in the E3 TRAN Status and Diagnostics Options Register has no affect on
the insertion of the justification service and the tributary justification bits through the TOH and
the TOHINS inputs.
Figure 55 Transmit J2 Overhead
J2 Multi-Frame Period
TOHFP
...
...
...
...
...
...
...
...
TOHCLK
TOH
1
1
0
0
m1
e1 e2 e3 e4 e5
TOHINS
TS97
TS98
TS97
TS98
TS97
The Transmit J2 Overhead diagram (Figure 55) shows the insertion of J2 overhead bits using the
TOH and TOHINS inputs. The TOHFP output is set to logic one once per J2 multiframe (for the
first bit of TS97 in the first frame of the J2 multiframe). TOHCLK is a gapped clock which will
pulse at a maximum instantaneous rate equal to the TICLK frequency. When TOHINS is a logic
one, the TOH input pin state replaces that generated within the J2 TRAN block. TOH and
TOHINS are sampled on the rising TOHCLK clock edge.
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
309
PMC [ PMC-SIERRA, INC ]
