Preliminary Data Sheet
May 2001
TMXF28155/51 Super Mapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
435
Agere Systems Inc.
19 VT/TU Mapper Functional Description
(continued)
I
The pointer interpreter will transition into the DEC state based on the following conditions:
—
When operating in the 8 of 10 mode (VT_8ORMAJORITY = 1 (
Table 181
)), if 8 of the 10 I and D bits are correct
for a pointer decrement on the incoming V1 and V2 bytes, the pointer interpreter will transition into the DEC
state. Otherwise, if 3 of the 5 I bits and 3 of the 5 D bits are correct for a pointer decrement on the incoming V1
and V2 bytes, the pointer interpreter will transition into the DEC state.
I
The pointer interpreter will transition out of the DEC state based on the following conditions:
—
If NDF is enabled on the incoming V1 and V2 bytes, the pointer interpreter will transition from the DEC state
into the NDF state.
—
Following three consecutive superframes with all ones in the V1 and V2 bytes, the pointer interpreter will tran-
sition from the DEC state into the AIS-V state.
—
Following three new consecutive, consistent, and valid pointers, the pointer interpreter will transition from the
DEC state into the NORM state.
—
Following any three consecutive, consistent, and valid pointers, the pointer interpreter will transition from the
DEC state into the NORM state.
—
Following the number of consecutive invalid pointers programmed in bits VT_INV_NTIME[3:0] (
Table 183
), the
pointer interpreter will transition from the DEC state into the LOP-V state.
Pointer increments and decrements are monitored and counted internally. The performance monitoring reset signal
transfers the count to the holding registers for pointer increment (VT_PTR_INC[1
—
28][3:0] (
Table 208
)), and
pointer decrement (VT_PTR_DEC[1
—
28][3:0] (
Table 208
)) for microprocessor read and resets the running count
registers to 0. When SMPR_SAT_ROLLOVER = 1 (
Table 67
), the internal running counts will hold at their maxi-
mum value. Otherwise, the counts will roll over. The running count and holding register counts will be forced to 0, if
the SPE mapper is requesting AUTO AIS or VT_LOP[1
—
28] = 1 (loss of pointer) (
Table 177
) or VT_AIS[1
—
28] = 1
(VT AIS) (
Table 177
) (or VT_H4LOMF = 1 (loss of H4 multiframe alignment) (
Table 176
)).
LOP-V (VT_LOP) and AIS-V (VT_AIS) will be detected and reported to the microprocessor. Both the LOP-V and
AIS-V conditions will contribute to the VT/TU mapper automatic AIS generation that is driven over a 28-bit internal
output bus to the cross connect (XC). Any change in state of VT_LOP or VT_AIS will be reported to the micropro-
cessor via VT_LOP_D[1
—
28] and VT_AIS_D[1
—
28] (
Table 169
). Unless the appropriate mask bit is set
(VT_LOP_M[1
—
28] or VT_AIS_M[1
—
28]) (
Table 173
), VT_LOP_D[1
—
28] = 1 or VT_AIS_D[1
—
28] = 1 will gener-
ate an interrupt.
A check for VT/TU size mismatches is performed by comparing the expected VT/TU size bits (VT1.5 = 11,
VT2 = 10) with the actual received SS bits in the V1 byte. After three consecutive mismatches, size errors will be
reported with bit VT_SIZERR[1
—
28] (
Table 177
). Any change in state of VT_SIZERR[1
—
28] will be reported with
bit VT_SIZERR_D[1
—
28] (
Table 169
). Unless the VT_SIZERR_M[1
—
28] (
Table 173
) mask bit is set,
VT_SIZERR_D[1
—
28] = 1 will generate an interrupt.
The accepted pointer is stored and accessible by the microprocessor.
This block supports tributary loopback.
19.9 VT Termination (VTTERM)
The VTTERM logic block (in
Figure 39
) will perform all necessary functions to support complete VT/TU termination.
The following features are implemented.
19.9.1 V5 Termination
The V5 byte is checked for BIP-2 errors. If BIP-2 errors are detected, REI-V is transmitted in the V5 byte of the cor-
responding transmit VT, if enabled by bit VT_REI_EN[1
—
28] = 1 (
Table 198
). BIP-2 errors and reception of REI-V
in the V5 byte is counted on a per-superframe basis. BIP-2 errors can counted on either a bit or block basis
selected by bit, VT_BIT_BLOCK_CNT (1 = bit, 0 = block) (
Table 181
).