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TMXF28155 Super Mapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Preliminary Data Sheet, Rev. 1
October 2000
332
Lucent Technologies Inc.
M13/M23 Mux/Demux Block Functional Description
(continued)
DS2 Frame Generation
Each M12 mux generates a DS2 frame either from 4 DS1 signals multiplexed as specified in T1.107 and GR-499-
CORE when M13_DS1_E1Ny = 1 (Table 264), or from 3 E1 signals multiplexed using the format specified in ITU-T
Recommendation G.747 when M13_DS1_E1Ny = 0.
When M13_M12_MODEy[1:0] (Table 264) = 01/10, each M12 Mux is operating independently. In this case, the out-
put DS2 signals are retimed by the associated clocks. The edge of the clocks that is used to retime the data is user
provisionable to either the rising edge (M13_DS2M12_EDGEy (Table 271) = 1) or falling edge
(M13_DS2M12_EDGEy = 0). The AIS signal can be inserted into any DS2 output by setting
M13_DS2_FORCE_AISy (Table 272) to 1.
DS1 Mode
In the DS1 mode, the 4 signals interleaved to generate the yth DS2 signal are the outputs from DS1/E1 loopback
selectors 4y – 3, 4y – 2, 4y – 1, and 4y. Bits multiplexed into the second and fourth channels (from selectors 4y – 2
and 4y) are inverted before being interleaved (T1.107) when bit M13_MUXCH2_4_INVy (Table 264) = 1.
Loopback requests for a DS1 channel are indicated by inverting the third C bit for that channel (T1.107). This is
done when bit M13_DS1_LB_REQx (Table 264) is set to 1. The 4 M13_DS1_LB_REQx bits that affect the yth DS2
are 4y – 3, 4y – 2, 4y – 1, and 4y.
The X bit is set to the inverse of the remote alarm indication (RAI) bit (T1.107) M13_DS2_RAI_SENDy (Table 266).
For testing purposes, the M-frame alignment signal (normally 011) is generated with the last bit inverted (010) if
M13_DS2_MPINVy (Table 268) is set, and the M-subframe alignment signal (01) is generated as (00) if
M13_DS2_FINVy (Table 269) is set.
E1 Mode
In the E1 mode, the 3 signals interleaved to generate the yth DS2 signal are the outputs from DS1/E1 loopback
selectors 4y – 3, 4y – 2, and 4y – 1.
Although it is not part of the G.747 standard, loopback requests for an E1 channel can be indicated as in the DS1
mode by inverting the third C bit for that channel. This is done if the M13_DS1_LB_REQx bit is set. The 3
M13_DS1_LB_REQx bits that affect the yth DS2 are 4y – 3, 4y – 2, and 4y – 1.
The remote alarm indication (RAI) bit and the reserved bit are set to the value of M13_DS2_RAI_SENDy and
M13_DS2_RSV_SENDy (Table 267) register bits, respectively (G.747).
For testing purposes, the frame alignment signal (normally 111010000 as specified in G.747) is generated with the
last bit inverted (111010001) if M13_DS2_FINVy is set, and the parity bit is inverted if M13_DS2_MPINVy is set.
The first parity bit after a 0 to 1 transition of SMPR_BER_INSRT (Table 13) is also inverted if M13_DS2_P_BERy
(Table 270) is set to 1.