Hi
please I need help to understand this program of AT89S8252, what mean of some command where can i found help about this command please help

 

You need to underdstand the architecture of the 8051 before attempting to dissect the program. Then, look at the 8051 instruction set to unsdertsand each directive/instruction.

Try this Keil website http://www.keil.com/support/man/docs/is51/