Data Register(DR) : hold the operand(Data) read from memory
Accumulator Register(AC) : general purpose processing register
Instruction Register(IR) : hold the instruction read frommemory
Temporary Register(TR) : hold a temporary data during processing
Address Register(AR) : hold a memory address, 12 bit width
Program Counter(PC) :
»hold the address of the next instruction to be read frommemory
after the current instruction is executed
»Instruction words are read and executed in sequence unless a branch
instruction is encountered
»A branch instruction calls for a transfer to a nonconsecutive
instruction in the program
»The address part of a branch instruction is transferred to PCto become
the address of the next instruction
Input Register(INPR) : receive an 8-bit character from an input device
Output Register(OUTR) : hold an 8-bit character for an
output device
