HDLC 2 APB Bridge

Table of Contents

Introduction

HDLC frame to APB bridge , is cable of receive and transmit of HDLC frame .
The module is accessed through an APB slave from the host side.

The IP is targeting the following Applications:

  • Communication controllers in networking and telecommunication systems.
  • Automotive systems for reliable data transfer (e.g., over CAN or LIN gateways).
  • Industrial automation requiring HDLC connectivity with APB-based processors.

Feature list

  • Synchronous operation
  • 8-bit parallel back-end interface
  • Use external RX and TX clocks
  • Start and end of frame pattern generation
  • Start and end of frame pattern checking
  • Idle pattern generation and detection (all ones)
  • Zero insertion and removal for transparent transmission
  • Abort pattern generation and checking (7 ones)
  • Address insertion and detection by software
  • CRC generation and checking (CRC-16 or CRC-32 can be used, which is configurable at the code top level)
  • Configurable size FIFO buffers for low latency transfer
  • Byte aligned data (if data is not aligned to 8-bits, error signal is reported to the backend interface)
  • Q.921, LAPD, and LAPB compliant
  • APB slave interface for host operations

2 High level description

  • Flag — Identifies the beginning and end of a frame — 01111110 (7E Hex)
  • Address — Address of the station: Single byte
  • Control — Defines the frame type and is protocol dependent
  • Data — Data field may vary in length depending upon the protocol using the frame. Layer 3 frames are carried in the data field
  • FCS — Frame Check Sequence is used to verify the data integrity