Introduction Of 8051
The microcontrollers 8051 have an 8-bitdata bus.
They are capable of addressing 64K of program memory and a separate64K of
data memory. The 8051 has 4K of code memory implemented as on-chip Read Only
Memory (ROM). The 8051 has 128 bytes of internal Random Access Memory (RAM).
The 8051 has two timer/counters, a serial port, 4 general purpose parallel
I/O ports, and interrupt control logic with five sources of interrupts.
Besides internal RAM, the 8051 has various Special Function Registers (SFR),
which are the control and data registers for on-chip facilities. The SFRs
also include the accumulator, the B register, and the Program Status Word (PSW),
which contains the CPU flags. Programming the various internal hardware
facilities of the 8051 is achieved by placing the appropriate control words
into the corresponding SFR.