What is difference between the operating speed and internal bus frequency IN Micro controller?

 

What is difference between the operating speed and internal bus frequency IN Micro controller?

hi,
If 'operating speed' is the crystal frequency and the 'operating bus frequency' is the Instruction cycle time, then for most MCU's and PIC's it is a divide by 4 of the crystal frequency.

This will give 4 internal clock cycles for the CPU logic for each program Instruction.

E

 

The relationship is arbitrary. It depends on the internal architecture of the microcontroller. As has already been noted many PIC devices have a 4:1 ratio. Many 8051 parts have a 12:1 ratio, and many RISC machines have a 1:1 ratio. Sorry -- there is no general rule.

 

Only 8-bit PICs have the 4:1 ratio. The 16-bit ones are 2:1 and the 32-bit are 1:1.

Bob