Special function registers (SFR) memory in 8051 processor

In 8051 processor, for controlling some special functions, special function registers are used. Special function registers of 8051 processor are accumulator, B register, program status word, stack pointer, data printer 2 Byte, low Byte, high Byte, Port 0, Port 1, Port 2, Port 3, interrupt priority control, interrupt enable control, timer/counter mode control, timer/counter control, timer/counter 2 control, timer/counter 0 high Byte, timer/counter 0 low Byte, timer/counter 1 High Byte, timer/counter 1 low Byte, timer/counter 2 high Byte, timer/counter 2 low Byte, timer/counter 2 capture register high Byte, timer/counter 2 capture register low Byte, serial control, serial data buffer and power control. Stack pointer is a special function register in the stack area of the processor. The stack is a part of RAM where information is kept temporarily. Program status word is a special function register which is used for storing a number of important bits that are set and cleared by 8051 instructions. For the fine control of power control modes, power control register is used. For the better synchronization, configuration and modification of two timers in the 8051 processor, timer control register is used. For the configuration of on-board serial port, serial control register is used. The serial buffer is utilized for sending and receiving data through the on-board serial port. For arithmetic and logic operations, accumulator register is used in 8051 processor.