Dspic30F4011 PLL Settings

[mc@ey]

Hi All,

I am new in DsPic world. i often worked with pic18f family. In my Project i use dspic30f4011 with 10mhz quarz.

in my understanding i have a result from 2,5 MIPS

i would like to work with 4xPLL but i have no Idee, how can i set this in my source code.
i tryed with

#Fuses XT_PLL4

#use delay (Crystal= 10000000)

but it doesnt work.


Can somebody help me?

Thanks in advance.

[Ttelmah]

Start by looking in the .h file for the chip, and at the data sheet.
You will see in the data sheet, that unlike the PIC18, with just *4 PLL, you have a choice of *4, *8, and *16. However then you see (table 21-1), that the PLL can only be used with the XT oscillator, EC clock input, or FRC internal oscillator. However on these chips 'XT' is rated for up to 10MHz.
A look at the fuses, finds XT_PLL4, XT_PLL8, & XT_PLL16,

So you can run at 40MHz, with the first, and clock=40MHz, or go to 80MHz, with XT_PLL8. The fastest you can run the chip, is with a 7.5MHz crystal, and PLL16, giving 120MHz master oscillator, and 30MIPS.

The delay has to be given the clock rate. So either:

#use delay (clock=40MHz)

or

#use delay (crystal=10MHz, clock=40MHz)

If you do the latter, you can get rid of the PLL fuse, since the compiler then 'knows' to use the *4 PLL.

[mc@ey]

[mc@ey]

here is my Source Code;

#include <30F4011>
#Fuses NOWDT
#Fuses CKSFSM
#Fuses NOBROWNOUT

#device ICSP=1
#use delay( crystal=10MHz, clock=40MHz)
#use rs232(baud=38400,xmit=PIN_F3,rcv=PIN_F2)