how to configure 4xPLL ?

[daviz]

Hi everyone,

I tried to use PIC18F2331 with a 10MHz, configure as H4, but it cannot run.

is it correct to use the configuration below ?
#use delay(clock=40000000)
#fuses H4

or should it be this way?
#use delay(clock=10000000)
#fuses H4

Can someone guide me?

[asmallri]

When you set the H4 fuse don't forget you must power cycle the PIC or it will not use the multiplier.

This is the "most correct"

[treitmey]

asmallri are you sure about this. I have a 10MhZ clock and use the H4 fuse.
When I do ..
#USE DELAY(CLOCK=10000000)
#FUSES H4,HS,NOWDT,NOPROTECT,NOLVP
My serial ouput looks correct.

When I do ..
#USE DELAY(CLOCK=40000000)
#FUSES H4,HS,NOWDT,NOPROTECT,NOLVP
My serial output is garbage. Even after power cycle.

[TerryGiles]

Treitmey
You only need H4 in your fuse list. You have put H4,HS which probably
turns off the PLL multiplier. With 10MHz crystal and fuse H4 set clock to
40000000 as you suggest in your first example.

Regards

Terry

[treitmey]

with 1 liner program and ONLY H4 and a power cycle. Got good com and a 1.25Mhz. I think my 4x is working now.

#USE DELAY(CLOCK=40000000)
#FUSES H4,NOWDT,NOPROTECT,NOLVP


How is daviz doing??

[daviz]

Hi everyone,

Thanks very much.

I tried using
#use delay(clock=40000000)
#fuses HS

it works well.

But, at this configuration, the maximum baudrate that can be used is 38400.
When I use 24MHz clock, the baudrate can go up to 115200.
Am I correct?

Regards,
Daviz

[daviz]

i wrote wrongly above,

its not #fuses HS
it should be #fuses H4

[asmallri]