Posted on March 10, 2006 at 08:45I would be very glad to hear from any one who has used STR71x HDLC in serious application. Because I am starting to wonder if it has ever been used - even by ST.
Quite apart from there being much missing from the doco for HDLC and the bugs in the sample code, the main control bits REN and TEN do not work according to the manual.
If you write 1 to REN in PCR and read PCR then TEN is set when you read PCR back. REN is meant to stay set until a packet is received but it does not. These bits are meant to be simple read/write control bits but they aren't. In fact (TEN) bit 1 is mostly equal to what you wrote into (REN) bit 0 but if you write to (TEN) bit 1 it starts a transmission but does not set (TEN) bit 1 when you read it back (this may be because packet has gone and TEN is cleared).
Example Write 0x0001 to PCR and read PCR it will be equal to 0x0002.
Without these bits working the basic sytem is unusable.
The HDLC test in their sample works because they only poll for a packet when they know one is there (and it is only 10 bytes long) rather than waiting for a packet to come in from a remote source.
Would be glad to hear from any one who can explain these bits or if any one in the world has used STR71x HDLC in serious application.
