I programming in AT89C51.
I want to know when the new value appears in the out put pin ?

I am writing the information obtained from Intel h/w description of 8XC51. Whether it is correct for AT89C51 ? And is it true for all instructions which write values to port, like mov,setb etc .


A machine cycle consists of six stages (Stage1 to stage6) and each stage is divided into two phases, Phase1 and Phase2

In the execution of an instruction that changes the value in a port latch, the new value arrives at the latch during Stage6 Phase2 of the final cycle of the instruction. The new value appears at the output pin only at the Stage1 Phase1 of next instruction.
Prasad