2. REGISTER
A register is a group of flip-flops with each flip-flop
capable of storing one bit of information,
A processor register may hold an instruction, a
storage address, or any data,
The computer needs processor registers for
manipulating data and a register for holding a
memory address,
List of basic registers are as follows-
3. DR
Full form- Data register
Number of bits-16
The Data Register (DR) contains 16 bits which hold
the operand read from the memory location.
4. AR
Full form- Address register
Number of bits-12
The Memory Address Register (MAR) contains 12
bits which hold the address for the memory
location.
5. AC
Full form- Accumulator
Number of bits-16
The Accumulator (AC) register is a general purpose
processing register.
6. IR
Full form- Instruction register
Number of bits-16
The instruction read from memory is placed in the
Instruction register (IR)
7. PC
Full form- Program counter
Number of bits-12
The Program Counter (PC) also contains 12 bits
which hold the address of the next instruction to be
read from memory after the current instruction is
executed.
8. TR
Full form- Temporary register
Number of bits-16
The Temporary Register (TR) is used for holding
the temporary data during the processing
9. INPR
Full form- Input register
Number of bits-08
The Input Registers (IR) holds the input characters
given by the user.
10. OUTR
Full form- Output register
Number of bits-08
The Output Registers (OR) holds the output after
processing the input data.