gnupic: Thread: PIC16F871

Hi,

Finaly, my PIC16F84 programmer works properly. The PIC was faulty.

I found another IC named PIC16F871. It's cheaper, and has more features. My
question is. Does the burning protocoll differs to th 'F84? I know, that it
needs only 5V, and has a built in purning program. Can I program 871 with a
proper hardware by prog84?

Leva

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Leva wrote:
> Hi,
> 
> Finaly, my PIC16F84 programmer works properly. The PIC was faulty.
> 
> I found another IC named PIC16F871. It's cheaper, and has more features. My
> question is. Does the burning protocoll differs to th 'F84? I know, that it
> needs only 5V, and has a built in purning program. Can I program 871 with a
> proper hardware by prog84?

Well, for starters, the 16F871 is a 40-pin chip, so it may not even fit in your programmer. It's a dumbed-down version of the 16F877A, with less memory and minus the I2C/SPI interface. It's a fine choice, though, if that's what you need - and enough cheaper than the 877A to be worth the trouble. 

PICs often come in multiple variants; for instance, the 16F874A is exactly like the 877A, except with only half as much flash memory. (Some of the 874A chips are probably really 877A dice where some of the memory was defective.) But it's only about 30 cents cheaper, so people buying in small quantities usually go for the full-featured part, since you may need the extra program memory some of the time, and it's not worth the trouble to keep two kinds of chips around.

The usual suggestion for replacing the 16F84 is the 16F628 (to be replaced someday by the 16F628A); that's an 18-pin part like the 16F84, and almost completely upward-compatible. Because of the additional features in the newer part, programs sometimes need minor adjustments.

Any programming software needs minor changes for each model of PIC. The hardware requirements stay similar, so it's usually simple to adapt a programmer for older models to handle newer ones, assuming that both parts have the same number of pins. The reverse isn't always true; low voltage programmers designed for new chips won't work with the old ones that don't have the LVP feature.

On Mon, Apr 28, 2003 at 12:52:00PM +0200, Leva wrote:
> Hi,
> 
> Finaly, my PIC16F84 programmer works properly. The PIC was faulty.

It happens. Not often though.

> 
> I found another IC named PIC16F871. It's cheaper, and has more features. My
> question is. Does the burning protocoll differs to th 'F84? 

I'm sure that the bulk erase specification is different. Also the programming
time may be different.

The definitive source is the programming specifications. Microchip has each
and every programming specification online. One of the great things about PICs.

Finally it's always a good idea to ground the LVP/RB3 pin when programming to
prevent a possible low voltage/high voltage glitch when programming.

> I know, that it
> needs only 5V,

You can still program it using the high voltage. It save the abovementioned
LVP pin.

> and has a built in purning program.

Not exactly. The 871 can write its own program memory. So it's possible to load
a bootloader into it. However it's not built in.

> Can I program 871 with a proper hardware by prog84?

prog84 will probably have problems with the bulk erase and the memory size.

If it's a Tait style parallel programmer than maybe David Tait's FPP or Nigel
Goodwin's winpicprg may be a better choice.

BAJ