dsPIC33 with FRC Oscillator

[tripper269]

Hi all,

Does anybody know how set up the clock rate to 200 MHz by using internal FRC ? I tried with different fuse setting and #use delay(clock=4MHz, internal). use delay overrides the fuse settings. If i set the clock rate in ASM, use delay will change it. But in use delay the clock rate i can get is 80Mhz. So how can i achieve 200Mhz clock rate in CCS ?

[newguy]

I'm not aware of any dsPIC33 processors rated to run up to 200MHz. I know there are some E series parts rated to 140MHz, but I've never seen any rated higher than that.

What is the part #?

[Ttelmah]

You can simply check by opening the 'parametric chart' on the Microchip site, and selecting the 'CPU speed' column.
70mips is the fastest listed.

To run these at 140MHz, the delay statement, is:

#use delay(clock=140Mhz,internal)

'Of course' the delay overrides the fuse settings. The delay must match the speed the CPU is being clocked at.

Also though, most of the clock programming on these chips is not done by the fuses. The PLL is setup after the chip boots. The compiler calculates the settings for these based on the clock specified, and the clock source (so if you used 'crystal=10MHz', with the same 'clock' setting, it'd know to set the PLL up to give a *14 result).

[tripper269]

The part is dsPIC33FJ256GP506.I am using dsPIC starter kit, Labs comes with it says its running on 200MHZ and I also checked datasheet. All files are in XC16 but I decided to work on CCS cause that's what peoples use at my work. CCS is not allowing me to use more than 80Mhz speed with #use(clock =140Mhz, internal).

[temtronic]

Which compiler version ? could be old, updated version may have fixed it ?

Maybe report to CCS on their website.

Jay

[newguy]

http://www.microchip.com/wwwproducts/Devices.aspx?product=dsPIC33FJ256GP506

First line of that processor's specifications:

[Ttelmah]

That chip is only rated for 80Mhz.
Read the data sheet.

This is why CCS won't let you select above this.

The starter kit itself _is_ rated to 200MHz, but only with chips that support this. Currently only the dsPIC32 models offer this, with the PIC32MZ starter kit.