18Pin PICs 16F > 18F pinout changes.

Does anyone know why Microchip changed the pinout on the 18 pin chips between the 16F and 18F lines ? Specificaly the 16F88 and the 18F1320

Have you a reason why they shouldn't. As they are not code compatible, it would make sense to make them not pin compatible. Rewriting the code will enable 1320 code to work in a circuit that was designed for an 88.

What I would like to know is why Microchip divided the peripherals between the ports. Port A shares the main crystal. Port B the ICD2 and port C the serial port. Switch them around and there is no 16 series where you have an 8 bit port. It would have made more sense to put all peripherals on 1 port.

Mike.

Often pinouts are determined by the chip internals. Getting a nice orderly pinout requires extra chip design work. I am sure you know this but others may not.

Pommie said:

Have you a reason why they shouldn't.

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No, but I was thinking there may be some advantage behind the 18F pinout that I am not seeing.

... It would have made more sense to put all peripherals on 1 port

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I agree.

I think the 16F88 is the newer design, it also has a single redirectable I/O pin (the CCP pin) Perhaps the next 18F132x will follow this if they add an MSSP

The closest relatives between P16 and P18 that I've seen are the 16F877A and 18F452. They are virtually identical in pins and functions. Now the new 16F887 is here which has more P18 type hardware features and at half the price. I hope this trend in pricing follows with new releases.