Registers are used by the microprocessor for temporary storage and manipulation of data and instructions. Data remain in the registers till they are sent to the memory or I/O device. In a large computer the number of register is more and hence the program requires less transfer of data to/form the memory. In a small computer the number of registers is small due to limited size of the chip. Inter 8085 microprocessor has the following registers.
One 8-bit accumulator (ACC) i.e register A.
Six 8-bit general purpose registers. These are B, C, D, E, H, L.
One 16-bit stack pointer, S.P.
One 16-bit program counter, PC.
Instruction Register
Status register
Temporary register.