I did exactly that....did a jumper to power the PIC with 5V when and IF I needed to do a block erase. Mike Hord wrote:> I'm working on a project using the 18LF6520 running at 3.3V. As I read the > datasheet, we can do ICSP programming at this voltage (with high voltage > Vpp), but it does not appear we can erase the chip with this voltage > (datasheet page 319). Does it look like I'm reading this correctly? I think Microchip needs to put out a publication specifically dealing with this issue. It's pretty confusing and we've gone over it a few times just within the last several months. Are you looking at parameter D132, and D132A? If so, take heart. The limit is on block and externally timed erasing, NOT erasing in general. This becomes a limit in some cases, because, for example, Olin's ProProg performs a block erase first, then programs, which means (AIUI, from the last discussion) it would want to raise the Vdd above 4.5V to do the block erase, then proceed from there. If you use an ICD2, however, it doesn't do a block erase. What does that mean? It means either your programmer can't do a block erase (or you can't use a programmer that does a block erase) OR your system needs to be able to survive that brief excursion to 4.5+ V to allow the block erase. In my case, I went over the low voltage components I am using, and 5V is well within their "Absolute Maximum" range, meaning they won't die, even though they can't be used at that voltage. Or you can isolate the power coming to the PIC from the ICSP connector... Mike H. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --------------------------------- Start your day with Yahoo! - make it your home page -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist