DSPIC33 and setup_oscillator() problems.. a solution..

[ik1wvq]

HI all,

i try to use the SETUP_OSCILLATOR function with DS33.
The results was bad, and then i wrote this simple code to program
PLL and switch oscillator.
WARNING: this is valid ONLY for DS33.

Enjoy..
regards

Mauro ik1wvq

PS.: my english is bad, but the code is working!
---------------

// costants for "DS33_OSC_CONFIG()")
// first parameter (only one)
#define Fast_RC_Oscillator 0b00000000
#define Fast_RC_Oscillator_PLL 0b00000001
#define Primary_Oscillator 0b00000010
#define Primary_Oscillator_PLL 0b00000011
#define Secondary_Oscillator 0b00000100
#define Low_Power_RC_Oscillator 0b00000101
#define Fast_RC_Oscillator_Div16 0b00000110
#define Fast_RC_Oscillator_DivN 0b00000111
// second parameter (one or more ORed)
#define switch_osc 0b00000001
#define abil_SEC_OSC_LP 0b00000010
#define lock_modify_pin_IO 0b01000000
#define unlock_modify_pin_IO 0b00000000



void DS33_osc_config(unsigned int16 valueHI,unsigned int16 valueLO)
{
// VALID ONLY FOR DS33
#asm asis
MOV valueHI,w0
MOV #0x743, w1 ; OSCCONH 0x743
MOV #0x78, w2
MOV #0x9A, w3
MOV.B w2, [w1]
MOV.B w3, [w1]
; write valoreHI on OSCCONH
MOV.B w0, [w1]

MOV valueLO, w0
MOV #0x742, w1 ; OSCCONL 0x742
MOV #0x46, w2
MOV #0x57, w3
MOV.B w2, [w1]
MOV.B w3, [w1]
; write valoreLO on OSCCONL
MOV.B w0, [w1]
#endasm
}

[daraos]

Thanks Mauro! that's exactly what I was looking for, the clock in the 33f is a real pain in the neck. Now, what I can't do, is configure the pre, post & clockdiv, the 33f assembler is waaay too much for me. If I can make it work, I'll post my code, or if you already have it, please share!

EDIT:

I made it work

so, the final code to make a 33f work at nearly 40 MIPS with the internal oscillator is:

[logical]

Hi,

Sorry to dig up and old post but how would I go about using the above.

I have a DSPIC33FJ128GP804

Basically I can get it to run fine on the internal oscillator on 7.37M, as soon as I try to increase the speed using the PLL, problems start.
Even with doing SPI Writes, the clock scores under 2MHZ based on SPI_CLK_DIV_4

I have looked through the datasheets and fully understand the configurations but unsure where to change those values from within PICC.


Even tried with things like:
#use delay(clock=73.7M,internal)
#use delay(clock=73.7M,internal=7.37M) etc

THanks

Chris

[daraos]

Try pasting the code I posted inside the main. The delay should be clock=40M
The pic must start slow and in the code you must increase the speed. so, do it like this:

[logical]

Fantastic thanks, will give that a try later this evening and will post the result.

[petiot]

hi,
Looking at the assembly generated, this code should do it. I have not tried it though.