
Preliminary Data Sheet, Rev. 1
October 2000
TMXF28155 Super Mapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
261
Lucent Technologies Inc.
VT/TU Mapper Functional Description
(continued)
Receive Signaling (RX_VTSIG)
The RX_VTSIG logic block (in Figure 31 on page 248) will perform all necessary functions to extract and transmit
the received signaling bits when operating in DS1 byte-synchronous mode. The following features are imple-
mented:
I
The signaling is sent to the appropriate framer link selected by bits VT_RXSIG_CH_SEL[1—28][4:0]
(Table 204). VT_RXSIG_CH_SEL[1—28][4:0] is a necessary duplication of the routing information programmed
within the cross connect (XC) block.
I
When VT_SYNC_PBIT[1—28] = 1 (Table 204), the RX_VTSIG block will synchronize to the incoming VT/TU
phase indication (P1, P0). Otherwise, VT_LOPS[1—28] (Table 177) and VT_LOPS_D[1—28] (Table 169) will be
forced to 0.
I
P-bit phase synchronization (VT_LOPS[1—28] = 0) is declared following two consecutive nonerrored multi-
frames (48 frames). Loss of phase synchronization (VT_LOPS[1—28] = 1) is declared following the number of
consecutive errored multiframes programmed in bits VT_LOPS_NTIME[3:0] (Table 182). Any change in
VT_LOPS[1—28] state will be detected and reported to the microprocessor with bit VT_LOPS_D[1—28].
I
If the loss of phase synchronization (VT_LOPS[1—28] = 1) condition exists and VT_LOPS_AIS_INH = 0, DS1
AIS is transmitted downstream and the signaling bits will be forced to the value in SMPR_OH_DEFLT (Table 15)
in the MPU block. Otherwise (VT_LOPS[1—28] = 0), the VT_RX_VTSIG logic block will behave as described in
Table 148 below.
I
Unless VT_LOPS_M[1—28] (Table 173) mask bit is set, VT_LOPS_D[1—28] will generate an interrupt.
I
See Table 148 below for signaling behavior based on the receive status and control.
Table 148. Rx Signaling Behavior per Channel
* If the P1 and P0 bits are not used for phase indication and the F bit is not passed transparently, the F bit is overwritten with the appropriate
SF or ESF framing pattern based on a random starting position. Robbed-bit signaling will not be accessible under such a condition.
When operating in the ESF mode, the Ft bits will be overwritten with the ESF frame and the C and M bits passed transparently.
VT_SYNC_PBIT
[1—28]
(Table 204)
0
0
0
1
1
1
VT_WR_FBIT
[1—28]
(Table 204)
0
1
1
1
1
X
VT_SF_ESF
[1—28]
(Table 204)
X
0*
1
a
0
1
X
VT_LOPS
[1—28]
(Table 177)
X
X
X
0
0
1
Action
Pass F-bit transparently.
Overwrite outgoing F bit with ESF pattern.
Overwrite outgoing F bit with SF pattern.
Overwrite outgoing F bit with ESF pattern.
Overwrite outgoing F bit with SF pattern.
Transmit DS1 AIS downstream.