T7121 HDLC Interface for ISDN (HIFI-64)
Data Sheet
April 1997
Table of Contents
Contents
Page
Features ................................................................................................................................................................... 1
Description................................................................................................................................................................ 1
Pin Information ......................................................................................................................................................... 4
Functional Description .............................................................................................................................................. 8
Microprocessor Bus Interface ................................................................................................................................ 8
FIFO Memory Buffers ............................................................................................................................................ 9
HDLC Operation .................................................................................................................................................. 19
Using the Transmitter Status and Fill Level ...................................................................................................... 21
Transparent Mode................................................................................................................................................ 24
Diagnostic Modes ................................................................................................................................................ 25
Powerdown Mode ................................................................................................................................................ 28
Registers.............................................................................................................................................................. 28
Absolute Maximum Ratings.................................................................................................................................... 45
Electrical Characteristics ........................................................................................................................................ 45
Clock Characteristics.............................................................................................................................................. 46
Timing Characteristics ............................................................................................................................................ 46
TDM Frame Timing Diagrams.............................................................................................................................. 46
Multiplexed Address and Data ............................................................................................................................. 51
Separate Address and Data................................................................................................................................. 53
Concentration Highway........................................................................................................................................ 55
Handling Precautions ............................................................................................................................................. 59
Outline Diagrams.................................................................................................................................................... 60
28-Pin, Plastic DIP ............................................................................................................................................... 60
28-Pin, Plastic SOJ, Surface Mounting................................................................................................................ 61
Ordering Information............................................................................................................................................... 62
Appendix................................................................................................................................................................. 63
Transparent Mode................................................................................................................................................ 63
HDLC Mode ......................................................................................................................................................... 63
General Features ................................................................................................................................................. 64
Power and Ground............................................................................................................................................... 66
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