
TMXF28155/51 Super Mapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Preliminary Data Sheet
May 2001
450
Agere Systems Inc.
19 VT/TU Mapper Functional Description
(continued)
19.14.5 VT Multiplexer (VTMUX)
The VTMUX logic block (in
Figure 39 on page429
) performs all functions necessary to place the appropriate VT
data onto the outgoing mapper transmit path data bus.
Bits VT_TX_GRP_TYPE[6:0] (
Table 180
) are programmed to determine whether the outgoing tributary is a
VT1.5/TU-11 or a VT2/TU-12.
See
Table 551
through
Table 554
on
page 430
through
page 431
for VT/TU mapping formats.
19.14.6 Transmit Signaling (TX_VTSIG)
The TX_VTSIG logic block (in
Figure 39 on page429
) will perform all necessary functions to retrieve the signaling
phase and data from the framer and insert it into the outgoing VT/TU.
Note:
This block is only enabled when operating in the byte synchronous mode.
I
The signaling is received from the appropriate framer link selected with the value programmed in bits
VT_TXSIG_CH_SEL[1
—
28][4:0] (
Table 202
). VT_TXSIG_CH_SEL[1
—
28][4:0] is a necessary duplication of the
routing information programmed within the cross connect (XC) block.
I
The TX_VTSIG block determines whether the phase and signaling bits are to be used in the VT/TU mapping. If
the phase or signaling bits are not being used (VT_USE_PBIT[1
—
28] = 0, VT_USE_SBIT[1
—
28] = 0
(
Table 202
)), they will be set to SMPR_FXD_STFF_DEFLT (
Table 67
) in the microprocessor interface block.
Stomping of the F bit is controlled by VT_USE_FBIT[1
—
28] = 0 (
Table 202
). Refer to
Table 574
below for pro-
gramming signaling inserting.
Table 574. Framing Byte Generation Per Channel
* X
—
value based on SMPR_OH_DEFLT (
Table 67
), R
—
value based on SMPR_FXD_STFF_DEFLT (
Table 67
).
19.14.7 Transmit Lower Path Overhead (TX_LOPOH)
The TX_LOPOH logic block (in
Figure 39 on page 429
) performs all necessary functions to receive and store the
low-order path overhead as well as the REI and RDI values from the external LOPOH serial access channel. The
following functions are supported:
I
The TX_LOPOH logic block retimes all incoming signals on the falling edge of the external input pin
LOPOHCLKIN (AC13).
I
The source of the external inputs LOPOHDATAIN (AC14), LOPOHVALIDIN, and LOPOHCLKIN is required to
hold the LOPOHVALIDIN at 0 for a minimum of eight LOPOHCLKIN cycles. The TX_LOPOH logic block monitors
the incoming LOPOHVALIDIN and detects failure conditions. A failure exists if there are less than eight
LOPOHCLKIN cycles between a falling edge of LOPOHVALIDIN and the next rising edge, or if the internal bit
counter reaches its maximum count, for the active data type, and LOPOHVALIDIN does not transition to 0.
VT_USE_FBIT[1
—
28]
(See
Table 202
.)
0
0
0
0
1
1
1
1
VT_USE_PBIT[1
—
28]
(See
Table 202
.)
0
0
1
1
0
0
1
1
VT_USE_SBIT[1
—
28]
(See
Table 202
.)
0
1
0
1
0
1
0
1
Action
VT/TU frame byte* = XXXXXXXR
VT/TU frame byte* = XXS1S2S3S4XR
VT/TU frame byte* = P1P0XXXXXR
VT/TU frame byte* = P1P0S1S2S3S4XR
VT/TU frame byte* = XXXXXXFR
VT/TU frame byte* = XXS1S2S3S4FR
VT/TU frame byte* = P1P0XXXXFR
VT/TU frame byte* = P1P0S1S2S3S4FR