This is all for those PIC overclocking enthusiasts out there.
.........Overclocking is strictly for hobbyist use dont sell overclocked parts......... .
The PIC18f2550 is an 28pin USB capable microcontroller. It features a 48Mhz clock and 12MIPS instruction cycle and quite a lot of perepherals like USB,SPI,EUSART,ADC,PWM,timer's etc straight from Microchip, but guess what i just found...
The PIC18f2550 core is capable of speeds upto 80Mhz (20MIPS). Beyond that it stutters (had a lot of problems above that speed). The thing you can do is run the PIC from an external clock source (in my case i had run it with a 20Mhz clock).
Now set the internal PLL for 12MHZ(which is /3 ratio).
The PLL will now divide your 20Mhz clock by 3 giving you 6.66666667(roughly 6.7).
The PLL has an internal multiplier of 24 which makes a PLL output of 160.08 Mhz.
Now set the config bits for PLL/2 thus giving you a CPU clock of 80Mhz.
............................................................................................
I have not checked if the perepherals( ADC, PWM, USB ) run at that speed but the PORT functions are as usual. I can even run a GLCD (128x64) with the micro at this speed.
ENJOY
.........Overclocking is strictly for hobbyist use dont sell overclocked parts......... .
The PIC18f2550 is an 28pin USB capable microcontroller. It features a 48Mhz clock and 12MIPS instruction cycle and quite a lot of perepherals like USB,SPI,EUSART,ADC,PWM,timer's etc straight from Microchip, but guess what i just found...
The PIC18f2550 core is capable of speeds upto 80Mhz (20MIPS). Beyond that it stutters (had a lot of problems above that speed). The thing you can do is run the PIC from an external clock source (in my case i had run it with a 20Mhz clock).
Now set the internal PLL for 12MHZ(which is /3 ratio).
The PLL will now divide your 20Mhz clock by 3 giving you 6.66666667(roughly 6.7).
The PLL has an internal multiplier of 24 which makes a PLL output of 160.08 Mhz.
Now set the config bits for PLL/2 thus giving you a CPU clock of 80Mhz.
............................................................................................
I have not checked if the perepherals( ADC, PWM, USB ) run at that speed but the PORT functions are as usual. I can even run a GLCD (128x64) with the micro at this speed.
ENJOY
