PIC16f628a or PIC16f84ap for replacement of PIC16F628

[dope40]

hi, i am building a cdi unit ( **broken link removed** ) but i am facing a problem , i can't find PIC16f628 nowhere,all i can find is PIC16f628A-i/p , and in the parts list (**broken link removed** ) PIC16f84AP is presented as replacement ,so can you tell me if it will work with either one , and do i have to make any changes to the circuit or the code . and which one should i use.

 

[betwixt]

Re: PIC16f628 or PIC16f84ap

The differences between the 628 and 628A are very minor and in almost all circumstances the 628A will work as a direct replacement.

Some of the configuration bits are renamed although their function is still the same.
There is a change to the way code protection works, this shouldn't make any difference to functionality.
When TMR1 is tun in oscillator mode, it is optimized for 32KHz crystals instead of 200KHz.

For your application none of the differences are important and as it will work with the much older and simpler 16F84 it should work with the newer 628A.

Brian.

 

[dope40]

Re: PIC16f628 or PIC16f84ap

thanks :smile:

- - - Updated - - -

thanks :-D

 

[tpetar]

Re: PIC16f628 or PIC16f84ap

http://www.microchip.com/forums/m108394.aspx


FROM PIC16F84 to PIC16F628 Guide
http://talkingelectronics.com/pay/PIC/PIC-Page33.html

Microchip PIC16F84 ® PIC16F84A Migration Guide
http://ww1.microchip.com/downloads/en/DeviceDoc/30072b.pdf

 

[ALERTLINKS]

Re: PIC16f628 or PIC16f84ap

Code sise limit is 1K in 16F84 wheras its 2K in 16F628. If your code is more than 1K, it won't fit in 16F84. There is some memory allocation difference too, which may or may not bother.

 

[tpetar]

Re: PIC16f628 or PIC16f84ap

We should speak about migration from 84 to 628 not reverse, that is purpose of 628. In some cases reverse not possible.