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Modern CPU clock multipliers

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Sceadwian

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Can anyone provide any links for the operation of a modern CPU's clock generator? I'm asuming there's some sort of base crystal frequency on the board and then it's sent through a PLL synthesizer that's made for high numbers of multiplication.
 
hi,
The 18F452 datasheet gives a brief description of its internal PLL.
[Just in case you did'nt already know.]


**broken link removed**
 
Last edited:
Here's an example of setting up the internal OSC and 4*PLL for most 18F PIC's with Swordfish

Code:
Device  = 18F4520
Clock = 32
Config OSC = INTIO67

OSCTUNE.6 = 1                   // Enables PLL

OSCCON = %01111111       // Sets up the internal oscillator

'
'
' Continue with progam

Note - You must define the Clock speed to be 32 not 8 as PLL is used! This will ensure the compiler generates the right delays for other functions/procedures
 
No offense, but what does a walkthrough of configuring a PLL in a microcontroller in BASIC have to do with the OP's original question about the hardware used in clock generation for modern CPU's??
 
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