MT8977 Datasheet, PDF (1/26 Pages) Mitel Networks Corporation – ISO-CMOS ST-BUS™ FAMILY T1/ESF Framer Circuit

ISO-CMOS ST-BUS™ FAMILY MT8977
®
T1/ESF Framer Circuit (ACCUNET^® T1.5)
Preliminary Information
Features
• D3/D4 or ESF framing and SLC-96 compatible
• Two frame elastic buffer with jitter tolerance
improved to 156 UI
• Insertion and detection of A, B, C, D bits,
signalling freeze, optional debounce
• Selectable B8ZS, jammed bit (ZCS) or no zero
code suppression
• Yellow alarm and blue alarm signal capabilities
• Bipolar violation count, F_T error count, CRC
error count
• Selectable robbed bit signalling
• Frame and superframe sync. signals, Tx and Rx
• AMI encoding and decoding
• Per channel, overall, and remote loop around
• Digital phase detector between T1 line and ST-
BUS
• One uncommitted scan point and drive point
• Pin compatible with MT8976 and MT8979
• ST-BUS compatible
Applications
• DS1/ESF digital trunk interfaces
• Computer to PBX interfaces (DMI and CPI)
• High speed computer to computer data links
ISSUE 2
May 1995
Ordering Information
MT8977AC 28 Pin Ceramic DIP
MT8977AE 28 Pin Plastic DIP
MT8977AP 44 Pin PLCC
-40°C to 85°C
Description
The MT8977 is a variant of the MT8976 framer,
which has been enhanced to meet ACCUNET^® T1.5
wander tolerance (138 UI).
The MT8977 meets ESF and D3/D4 formats, and is
compatible with SLC-96 systems.
TxSF
C2i
F0i
RxSF
DSTo
DSTi
CSTi0
CSTi1
CSTo
XCtl
XSt
ST-BUS
Timing
Circuitry
Data
Interface
Serial
Control
Interface
Control Logic
2 Frame
Elastic Buffer
with Slip
Control
2048-1544
Converter
ABCD
Signalling RAM
DS1
Link
Interface
Remote &
Digital
Loopbacks
Phase
DS1
Detector
Counter
•
Figure 1 - Functional Block Diagram
ACCUNET^® T1.5 is a registered trademark of AT & T
C1.5i
RxFDLClk
RxFDL
RxA
RxB
TxA
TxB
TxFDLClk
TxFDL
RxD
E1.5i
E8Ko
V_SS
V_DD
4-99