Post by thread:[PIC] 16F54 osc ?

Hi all, I am trying to clarify whether a specific 16F54 chip (PIC16F54-I/P) is tied to a specific osc option (like it used to be on 16C54XT/P-04 f.ex.). Iow, are all the osc options available on a (PIC16F54-I/P) or are they limited as on a 16C54XT/P-04. Also, I'd like to know where this is specified in the migration guide or other documentation. thanks, Peter

> I am trying to clarify whether a specific 16F54 chip > (PIC16F54-I/P) is tied to a > specific osc option (like it used to be on 16C54XT/P-04 > f.ex.). Iow, are all the > osc options available on a (PIC16F54-I/P) or are they limited as on a > 16C54XT/P-04. I don't fully understand the question. A -04 chip is of course limited to 4 MHz, so it can't use a higher frequency crystal, and hence it can't use an OSC option that requires a higher frequency crystal. The -I/P has no 'chip' frequency limit, so it is limited only by what the datasheet specifies. > Also, I'd like to know where this is specified in the migration > guide or other documentation. If I understand you correctly that is not an issue for migration: -1/P option are a superset of -04 options. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: http://www.voti.nl/hvu

On Feb 7, 2007, at 3:12 AM, Wouter van Ooijen wrote: >> I am trying to clarify whether a specific 16F54 chip >> (PIC16F54-I/P) is tied to a >> specific osc option (like it used to be on 16C54XT/P-04 >> f.ex.). Iow, are all the >> osc options available on a (PIC16F54-I/P) or are they limited as on a >> 16C54XT/P-04. > > I don't fully understand the question. A -04 chip is of course limited > to 4 MHz, so it can't use a higher frequency crystal, and hence it > can't > use an OSC option that requires a higher frequency crystal. In the original 16C54, clock oscillator configuration was controlled by a fuse bit that was (of course) not reprogrammable. While there was a rumor that you could program the fuse bits ONCE if you got the version that had them all unset, the usual procedure was to order the chips with the oscillator type already programmed. Thus, you'd order a PIC16F57/LP and could only run the low speed oscillator. The 16F5x datasheet doesn't make it explicit whether the config bits as well as the program memory are now flash and reprogrammable. I'd like to assume so, but it's a good question... BillW

William "Chops" Westfield <westfw <at> mac.com> writes: > The 16F5x datasheet doesn't make it explicit whether the config bits > as well as the program memory are now flash and reprogrammable. I'd > like to assume so, but it's a good question... Yes, I'd like to assume that too, but now I need to *know*. Do I have to talk to a FAE ? Would he know ? Where does one ask technical questions like this ? thanks, Peter --------------------------------- It's here! Your new message! Get new email alerts with the free Yahoo! Toolbar.