8051 microcontroller

8051 MICROCONTROLLER


Features of 8051 microcontroller
 8-bit CPU
 16-bit Program Counter
 8-bit Processor Status Word (PSW)
 8-bit Stack Pointer
 Internal RAM of 128 bytes
 Special Function Registers (SFRs) of 128 bytes
 32 I/O pins arranged as four 8-bit ports (P0 - P3)
 Two 16-bit timer/counters: T0 and T1
 Two external and three internal vectored interrupts
 One full duplex serial I/O
8051 MICROCONTROLLER ARCHITECTURE




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, The various components of 8051 Microcontroller are as follows:
CPU (Central Processing Unit):
 Composed of ALU, Program Counter, Data Pointer, Stack Pointer, Special Function or Special
Purpose Registers.
 ALU composed of Accumulator, B-Register and two Temporary Registers and PSW (Program
Status Word).
Accumulator
 8-bit register widely used for all arithmetic and logical operations.
 Accumulator is also used to transfer data between external memory.
 B-register is used along with Accumulator for multiplication and division.
 The contents of Accumulator and B-register are applied to ALU through their respective temporary
registers.


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