SA9101 Ver la hoja de datos (PDF) - South African Micro Electronic Systems
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SA9101 Datasheet PDF : 40 Pages
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SA9101
Synchronization procedure
Multiframe alignment is assumed to have been lost if double-frame alignment has been
lost or 2 consecutive multiframe patterns are received with an error.
The multiframe re-synchronization procedure starts when doubleframe alignment has
been regained. It may also be invoked by the user through the µP-interface. The CRC
checking mechanism will be enabled after the second correct multiframe pattern has
been found. However, CRC errors will not be counted in unsynchronized state.
The (multiframe) synchronized state is reached after detecting two correct multiframe
alignment patterns in multiframe n and multiframe n+1. The CRC4 flag SR0B1 will be
reset. Resynchronization starts whenever two consecutive multiframes are received
with incorrect multiframe alignment pattern.
Sub-
Multiframe
I
Multiframe
II
Frame
No.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
12
C0
1
01
C0
2
01
C3 0
11
C0
4
01
C1 0
11
C0
2
11
C0
3
S* 1
i
C0
4
S* 1
i
Bits 1 to 8 of the frame
3456 78
0 11 0 11
AS S S SS
n0
n1
n2
n3
n4
0 11 0 11
ASS S SS
n0
n1
n2
n3
n4
0 11 0 11
AS S S SS
n0
n1
n2
n3
n4
0 11 0 11
A Sn0 Sn1 Sn2 Sn3 Sn4
0 11 0 11
AS S S SS
n0
n1
n2
n3
n4
0 11 0 11
A Sn0 Sn1 Sn2 Sn3 Sn4
0 11 0 11
ASS S SS
n0
n1
n2
n3
n4
0 11 0 11
ASS S SS
n0
n1
n2
n3
n4
S *:
Spare bits for international use. Access to received information via µP-
i
interface. (For transmission, automatic transmission of sub-multiframe error
or insertion through µP-interface is selectable).
S:
Spare bits for national use. Additionally, the 5-byte stacks for receive and
n
transmit are provided.
C1..C4: Cyclic Redundancy Check bits.
A:
Remote Alarm Indication.
16/40
Table 2: CRC-Multiframe Structure
sames
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