N Nanya New Member Nov 19, 2007 #1 Hi guys, I just wanted to ask. Does a PIC16F877A MCU need a 20MHz crystal oscillator or you can use any crystal even those that have a frequency as low as 4MHz or 1MHz??? Thanks, Nanya
Hi guys, I just wanted to ask. Does a PIC16F877A MCU need a 20MHz crystal oscillator or you can use any crystal even those that have a frequency as low as 4MHz or 1MHz??? Thanks, Nanya
D Diver300 Well-Known Member Most Helpful Member Nov 19, 2007 #2 Most PICs, including the PIC16F877A, can be clocked as slowly as you want. The biggest problem with running slowly is getting crystals that low to run properly. If you need to run below about 4 MHz, I would suggest:- RC oscillator External crystal oscilator that contains a divider Watch crystal Watch crystals are a totally different form of crystal to the other types, and most PICs have a setting designed just to drive those.
Most PICs, including the PIC16F877A, can be clocked as slowly as you want. The biggest problem with running slowly is getting crystals that low to run properly. If you need to run below about 4 MHz, I would suggest:- RC oscillator External crystal oscilator that contains a divider Watch crystal Watch crystals are a totally different form of crystal to the other types, and most PICs have a setting designed just to drive those.
blueroomelectronics Well-Known Member Nov 19, 2007 #3 If you don't care about the frequency and just want something that runs you can use a resistor & capacitor as a clock. Or better yet a 16f887
If you don't care about the frequency and just want something that runs you can use a resistor & capacitor as a clock. Or better yet a 16f887
Nigel Goodwin Super Moderator Most Helpful Member Nov 20, 2007 #4 Diver300 said: Most PICs, including the PIC16F877A, can be clocked as slowly as you want. Click to expand... Even down to DC! - which means you can single step the PIC clock.
Diver300 said: Most PICs, including the PIC16F877A, can be clocked as slowly as you want. Click to expand... Even down to DC! - which means you can single step the PIC clock.