Post by thread:16C74 BRGH bug

Very sorry to rehash this - but as usual I wasn't paying attention in class....and now the problem has bitten me. A product has fallen into my lap with a 16C74, using the USART for asynchronous RX with the BRGH bit set. It isn't working properly (at all?) when configured for 8 data bits + parity. The only microchip documentation I found was the April '96 errata stating "a high number of receive errors may be experienced". I've experienced zero problems with 8 data bits and no parity. Can anyone point me towards a more detailed description of this bug? Thanks -mike -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Mike Fahrion spam_OUTmfahrionTakeThisOuTbb-elec.com http://www.bb-elec.com/ B&B Electronics Mfg Co ph.(815) 433-5100 ext.215 fax (815) 434-7094 707 Dayton Road PO Box 1040 Ottawa IL 61350 -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Mike Fahrion wrote: > A product has fallen into my lap with a 16C74, using the USART for > asynchronous RX with the BRGH bit set. It isn't working properly (at > all?) when configured for 8 data bits + parity. The only microchip > documentation I found was the April '96 errata stating "a high number > of receive errors may be experienced". I've experienced zero > problems with 8 data bits and no parity. Well, I'm using the 16C65, but the same language is used in that part's errata sheet. I was receiving 16-byte packets at 9600 baud (BRGH=1), with bit 8 used as an address flag -- I never tried it without the parity/bit 8. Results observed were: 10-20% of received packets were corrupted. Upon closer examination, a single character within each corrupted packet was found to be corrupted. ----------------------------------------- Frank Latos, Duo Systems Inc. .....flatosKILLspam@spam@mich.com -----------------------------------------