HDLC controller

Features

- 8 bit parallel backend 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)
- Idle pattern is assumed only after the end of a frame which is signaled by an abort signal
- Zero insertion
- Abort pattern generation and checking
- Address insertion and detection by software
- CRC generation and checking (Optional, external, since CRC-16 or CRC-32 can be used)
- FIFO buffers and synchronization (External)
- Byte aligned data (if data is not aligned to 8-bits extra random bits are inserted)
- Q.921, LAPB and LAPD compliant.
- For complete specifications refer to spec document

IMAGE: HDLC_top.jpg

FILE: HDLC_top.jpg
DESCRIPTION: Core top block diagram

Status

The VHDL code is ready in the opencores CVS. The code needs verification contact me if you are intrested in helping me.

- also see Download section

Resource usage

Rx Channel Block: which includes HDLC Framing extraction, zero removal and conversion from serial to parallel.

Vendor	Device	Size	Frequency	Board Tested	Functional Test	Notes
Altera	EP20K100BC356-3	108 LCs	91.48MHz	-	-	No optimization was peroformed, using Quartus II

Tx Channel Block: which includes HDLC Frame generation, zero insertion and conversion from parallel to serial.

Vendor	Device	Size	Frequency	Board Tested	Functional Test	Notes
Altera	EP20K100BC356-3	100 LCs	112.42MHz	-	-	No optimization was peroformed, using Quartus II

HDLC controller Block: which includes both the Rx and Tx channels, FCS-16 generation and checking, 128 byte buffering for each direction and Wishbon SOC bus interface and controller registers.

Vendor	Device	Size	Frequencies (MHz)	Board Tested	Functional Test	Notes
Altera	EP20K100BC356-3	630 LCs, 2 ESBs	CLK_I=74.02, RxClk=101.86, TxClk=106.42	-	-	No optimization was peroformed, using Quartus II

Links

• http://www.rad.com/networks/1994/hdlc/hdlc.htm
• http://www.erg.abdn.ac.uk/users/gorry/course/dl-pages/hdlc-framing.html
• http://members.tripod.com/~vkalra/hdlc.html
• http://goanna.cs.rmit.edu.au/~ivan/cs361/lec/lec5.pdf
• http://www.inicore.com/____pdf/inihdlc.pdf
• http://www.mentorg.com/inventra/netlist_program/actel/ds/hdlccoreA1_pd.pdf