MT8926AE Zarlink Semiconductor, MT8926AE Datasheet - Page 8

• Manufacturer Part Number: MT8926AE
• Description: MT8926 - T1 Performance Monitoring Adjunct Circuit (PMAC)
• Manufacturer: Zarlink Semiconductor

1.2
The MT8926 functions may be suspended by making the RESET input low (RESET must be high for normal
operation). In the reset state, data entering the PMAC on FDLi, DSTi0 and CSTi0 will pass through unaltered to
FDLo, DSTo and CSTo respectively. E8Ko will be high, IRQ will be high impedance and the 1SEC output (and TMR
bit) will be low.
After the MT8976/77 has acquired frame synchroni-zation and RESET returns high, the MT8926 will require two
superframes to acquire synchronization and two ST-BUS frames to align to the ST-BUS. RESET can be used to
prevent DS1 interface interrupts from occurring during system initialization. It should be noted that when the
MT8926 is acquiring synchronization the CRC and BPV counters may record errors.
MT8926
8
PCSW = Per Channel Status Word
PSW = Phase Status Word
* MT8976/77 Data unaltered by
CSTo
T1
the MT8926
7-5
ST-BUS Transmit
ST-BUS Receive
Data Stream
Data Stream
PMAC Miscellaneous
Bit
LCW = Loopback Control Word
4
3
2
1
0
Status Word
PCSW
0-2
1-3
Function
Not Used
LLDD (001)
LLED (00001)
FECV
TMR (2SEC)
BOMV
PMAC RESET
PS
W
3
PCSW
4-6
4-6
Figure 5 - CSTo Channel Allocation Versus T1 Channels
PM
SW
7
DSTi0
DSTi1
Check-6 Error Counter
Figure 6 - Payload and Line Loopback Operation
Cyclic Redundancy
Bit
Repeating
Repeating
7
0
PCSW
8-10
00001
7-9
Bit
7*
6*
5
4
3*
2
1*
0*
001
Master Status Word 1
Function
MSB
LSB
CRC
MT8926
11
YLALR
MIMIC
ALRM
RAI (ESF YELLOW)
MFSYNC
LOS
SLIP
SYN
Function
LCW
PCSW
12-14
10-12
To PMAC
Control
4 to 1 MUX
MS
W1
15
PCSW
16-18
13-15
7-4
3-0
Bit
Bipolar Violation Counter
CSTi1
DSTo
Errored Frame
Event Counter
Bit
7
0
EC
SE (MSB-LSB)
FE (MSB-LSB)
EF
19
Function
PCSW
20-22
16-18
Function
MSB
LSB
BPV
23
From System
Control
LCW
0 0
0 1
1 0
1 1
PCSW
24-26
19-21
Received Bit-Oriented
Bit
Message Register
2
7
0
DSTi0 to DSTo
DSTi1 to DSTo
00001 to DSTo (activate)
001 to DSTo (deactivate)
Bit
7*
6*
5*
4
3
2
1
0
BOM
CSTi1
DSTi
Function
DSTo
Function
27
Rx
Received First
Received Last
MT8976/77
Master Status Word 2
PCSW
28-30
22-24
Function
Data Sheet
BlAlm
FrCnt
Xst
SEI
FSI
CSI
BSI
AIS
TxB
TxA
MS
W2
31
RxA
RxB
ECLK
SEMICMF.019