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Hi! I'm a newbee. I know that -04 stands for 4 MHz, so if I use PIC16F84A-04/P, is this mean that I should clock the PIC with a 4 MHz clock? another question is, how will you know if a PIC is damage?


New Member
As low as 32KHz

Electronics Novice

Joined: 19 Aug 2003
Posts: 27

Posted: Fri Aug 29, 2003 8:53 am Post subject: 1111


it's not the crystal, it's probably the serial communication between the computer and the programmer

i used my pic16c84-04 with 10, 14.318, and EVEN 16 MHZ crystals and they were working fine, i would assume that pic16f84-04's would work as well with 10 or so MHZ crystals

p.s. the pic16f84a-20 can even handle speeds upto 25 MHZ

(verified by me)

also, it is not necesssary to use exactly 4MHz...You can use even 32KHz. you can refer to application note AN582 from Microchip official website

panic mode

Well-Known Member
If I understand correctly, clock speed specified on chip is the maximum speed that will guaranteed work with that chip. Since PIC controllers are fully static devices, you can build external oscillator such as multivibrator with 555 chip and run it as low as 1Hz if you really want to. Most chips can be overclocked but this is something that needs to be tested on case by case basis.


New Member
Monkeyxp I bought a 24 MHz x'tal for my 18F84a -20/p, I knew 16/32bit PC MCU could be overclocked and just assumed it would be the same with a PIC. Haven't tried it yet though, thanks.

tamethetikbalang orgininal post asks "how will you know if a PIC is damage?"

this I would also like to know.

Many times I thought I had fried one, and the thing keeps running, however after I program the PIC I get a brief and very fleeting error msge 'Fuse blown 0x3FFF'. I have cheked the .inc file and know the particular fuse setting. Is this ireversible and could it be affecting the pic's performance?
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