MICROPROCESSOR AND MICROCONTROLLER

Detailed explanation-1: -The Accumulator, as its name suggests, is used as a general register to accumulate the results of a large number of instructions. It can hold an 8-bit (1-byte) value and is the most versatile register the 8051 has due to the shear number of instructions that make use of the accumulator.

Detailed explanation-2: -Special Function Registers (SFR’s) In 8051 micro controller there are 21 Special function registers (SFR) and this includes Register A, Register B, Processor Status Word (PSW), PCON etc etc. There are 21 unique locations for these 21 special function registers and each of these register is of 1 byte size.