No access to all 24FJ256GA110 pins

[Mathy]

Hello,

I'm trying a 24FJ256GA110 but I have no access to the RC1 pin for exemple. Only the 2, 3 and 4.

What's the problem ?

Thank you for your help

Mathy.

[Sean]

There was an error in the FCD file for the chip. Here is an update with the RC1 fault corrected:

24FJ256GA110.fcd

(15.74 KiB) Downloaded 376 times

The file should be copied into the FCD folder of your Flowcode installation - overwriting the original. Flowcode should be closed when you do this.

[Mathy]

Hi,

Thank you Sean.

Works well

I have a problem now with the external oscillator. I use exactly the same 10Mhz oscillator I use on 18F family.
I think I set all the necessary fuse in the configuration menu but to have the good timing, I have to set 4 Mhz in the project menu.

Do you know what is the problem ?

[Sean]

The oscillator on the PIC24 devices is particularly complicated. In addition to the CONFIG fuses, there are programmable registers that affect initial calculations and allow changes to be made during program execution.

Your 4MHz estimation does not relate easily to the 10MHz xtal, but is one of the internal FRC clock frequencies. If possible, you could remove the xtal and see if the program still runs (confirming selection of the correct clock source).

Alternatively, you could post a simple LED flasher program on the forum, with a description of the timings you are observing, and see if anyone can check the settings.

[Mathy]

You are right. Without the 10Mhz oscillator, The program running well at 4 Mhz.

Changing the fuse setting about oscillator function has no effect

[Benj]

Hello,

Please post up your Flowcode file and I will have a look at your config settings for you. Could be you also need to write to the oscillator control registers at the start of your program if your using the onboard PLL.

On the dsPIC and PIC24 devices I think the XT oscillator type will run crystal frequencies up to 10MHz and HS will allow crystals over 10MHz.