Thanks for clarifying that... -----Original Message----- From: Gary Olmstead [mailto:] Sent: Monday, June 30, 2003 7:58 PM To: Subject: RE: [68HC12] Minimum equipment to re-program HC12 It is in the book called 68HC912D60 Advance Information, Rev 2.0. Dated July 27, 2000. Motorola part number MC68HC912D60/D. Page 86, fourth paragraph. However, this is for a _very_ different FLASH architecture compared to what you have. I am certain that it also appears in an ap-note, but it is on my "other" computer, which is across town, and I won't be back there this week. A quick search at Motorola failed to turn it up. I have actually seen this happen. It was repeatable enough that I was able to capture the sequence on a logic analyzer. The process was quite interesting, but too long to detail here. The short answer is that it was caused by the fact that we didn't have one of those reset control ICs, and our power supply did some very weird things at shut down. I should also add that this was on an MC146805E2, which treated undefined instructions as NOPs. The memory that it reprogrammed was an external EEPROM. I would say that you are probably OK, and I have my data confused. Wouldn't be the first time. Gary Olmstead Toucan Technology Ventura CA At 08:19 PM 6/30/03 +0200, you wrote: > >Who at Motorola "specifically recommends against this (because of the danger >that runaway code could get to the reprogramming block)"? Is there an APP >note or engineering bulletin? I have operated with a serial download >monitor for almost 2 years on a DG128A platform and have had ZERO problems. >If you lock the boot block ppage ASAP on startup (this is a write once >register), have a good reset generator, clean power, etc. then in my >experience, a serial downloader is very reliable. > >If there is an issue that Motorola has with this technique I would sure like >to know! > -------------------- ">http://docs.yahoo.com/info/terms/ This e-mail and any files transmitted with it ( Message ) are confidential and may contain privileged information. This Message is intended solely for the addressee(s). If you have received this Message in error, please inform us promptly by reply e-mail then delete the Message and destroy any printed copy of it. Any unauthorized use, review, retransmission, dissemination, distribution, printing or copying of this Message or any part thereof is strictly prohibited. E-mails are susceptible to alteration. Neither Technip-Coflexip nor any of its subsidiaries and affiliates shall be liable for the Message if altered, changed or falsified |