Machine cycle to clock cycle conversion in at89s52

Thread Starter


Joined Jul 12, 2016
I own an at89c2051 and an at89s52.

I'm able to successfully program LCD's with at89c2051 but not so well with at89s52.

I assumed the ratio between machine cycles and clock cycles is the same in both kinds of chips but maybe now I'm wrong.

In the at9c2051 datasheet under the reset description it states "Each machine cycle takes 12 oscillator or clock cycles", however I can't find such literature in the at89s52 datasheet.

How many oscillator cycles are there to a machine cycle in an at89s52?

Then according to, I can divide crystal frequency by the ratio (which is 12 for at89c2051) to find out how many seconds it takes for about 1/2 a command or 1 command to be processed, since some commands require 2 machine cycles to process.