I'm a research student working on error checking methods with the 8051 family of microcontrollers and I need to know during which oscillation cycle (eg S1P2, S3P1) would the program counter (PC) be incremented to point to the location of the next executable instruction.

I would also like to know the detailed fetch-decode-execute sequence of single and multiple byte instruction. In short, can anyone help me by pointing to some resource location with the detailed working of the 8051 processor core? Your help would be greatly appreciated. Thank you.