Registers 8086

  • General Purpose Registers:- 
8086 Microprocessors has 8 general purpose registers, each register has its own name:
  1. AX :- the accumulator register (divided into AH/AL)
  2. BX :- the base address register (divided into BH/BL)
  3. CX :- the count register (divided into CH/CL)
  4. DX :- the data register (divided into DH/DL)
  5. SI :- source index register
  6. DI :- destination index register
  7. BP :- base pointer.
  8. SP :- stack pointer.
  • Segment Register:-
  1. CS :- pointer at the segment containing the current program.
  2. DS :- generally points at segment where variables are defined.
  3. ES :- extra segment register, its up to coder to define its usage.
  4. SS :- points at the segment containing the stak
  • Special Purpose registers:-
  1. IP :- the instruction pointer.
  2. Flags Register :- determines the current state of the processor.
The Bus Interface Unit (BIU) contains the following registers::-
  • IP - the Instruction Pointer
  • CS - the Code Segment Register
  • DS - the Data Segment Register
  • SS - the Stack Segment Register
  • ES - the Extra Segment Register

Internal Registers of 8086

EU Registers
(Execution Unit)
AX
AH
AL
Accumulator
BX
BH
BL
Base Register
CX
CH
CL
Count Register
DX
DH
DL
Data Register

SP
Stack Pointer

BP
Base Pointer

SI
Source Index Register

DI
Destination Index Register



FR
Flag Register


BIU Registers
(Bus Interface Unit)

CS
Code Segment Register
DS
Data Segment Register
SS
Stack Segment Register
ES
Extra Segment Register

REFERENCE
  1. Microcomputer Systems: 8086/8088 Family - Architecture, Programming, and Design; Y. Liu and G. A. Gibson, 2nd Ed., PHI.
  2. Microprocessor & Interfacing – D. Hall, TMH
  3. The 8086 Microprocessor: Programming & Interfacing the PC, Kenneth J. Ayala, Penram International Publishing (India).
  4. The Intel 8086/8088 Microprocessor Architecture, Programming Design & Interfacing – B.S. Chhabra, Dhanpat Rai Publishing Company.
  5. The Intel Microprocessor 8086/8088, 80186/80188, 80286, 80386, 80486, Pentium & Pentium Pro Processor: Architecture, Programming & Interfacing – Brey & Sharma, Pearson Education.
  6. Advanced microprocessor, Rajasree, New Age International Publishers
  7. Fundamentals of Microprocessor and Microcomputers – B. Ram, Dhanpat Rai Publishing Company.
  8. Microprocessors: Principles and Applications by A Pal
  9. Advanced Microprocessors and Peripherals by A K Ray and K M Bhurchandi
  10. Microprocessors and Microcontrollers : Architecture, Programming and Interfacing Using 8085, 8086 and 8051 by Soumitra Kumar Mandal
  11. Introduction to Microprocessors and Microcontrollers by Crisp John Crisp
  12. Microprocessors And Microcontrollers by A Nagoor Kani
  13. Microprocessors And Microcontrollers : Architecture, Programming and System Design 8085, 8086, 8051, 8096 by Krishna Kant
  14. Microprocessors and Interfacing by Nikhil Marriwala, Katson Book, January, 2009

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