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STANDARD PRODUCT
PM8315 TEMUX
DATASHEET
PMC-1981125
ISSUE 7
HIGH DENSITY T1/E1 FRAMER WITH
INTEGRATED VT/TU MAPPER AND M13 MUX
PROPRIETARY AND CONFIDENTIAL
237
In normal E1 mode, the first 21 sets of clock and data pins are used in each
direction. The clock and data pins numbered between 22 and 28 are not
defined, as the 22
nd
through 28
th
framer blocks are not used in this mode.
In ITU-T G.747 mutiplexed E1 mode, every fourth set of clock and data pins are
not used in each direction. (i.e. Pins 1-3, 5-7, 9-11, 13-15, 17-19, 21-23, 25-27
are defined while pins 4, 8, 12, 16, 20, 24, and 28 are not defined.) This is
because the 4
th
, 8
th
, 12
th
, 16
th
, 20
th
, 24
th
and 28
th
framer blocks are not used in
this mode.
12.14 PRGD Pattern Generation
The pattern generator can be configured to generate pseudo random patterns or
repetitive patterns as shown in Figure 47 below:
Figure 47
- PRGD Pattern Generator
1
2
3
32
LENGTH
PS
TAP
The pattern generator consists of a 32 bit shift register and a single XOR gate.
The XOR gate output is fed into the first stage of the shift register. The XOR
gate inputs are determined by values written to the length register (PL[4:0]) and
the tap register (PT[4:0], when the PS bit is low). When PS is high, the pattern
detector functions as a recirculating shift register, with length determined by
PL[4:0].
Generating and detecting repetitive patterns
When a repetitive pattern (such as 1-in-8) is to be generated or detected, the PS
bit must be set to logic 1. The pattern length register must be set to (N-1), where
N is the length of the desired repetitive pattern. Several examples of
programming for common repetitive sequences are given below in the Common
Test Patterns section.
For pattern generation, the desired pattern must be written into the PRGD
Pattern Insertion registers. The repetitive pattern will then be continuously