8255 microprocessor operating modes 8086 Microprocessor

PROGRAM NO.8

OBJECT:Write a program to read 8-bit data from port B. Complement this data & send it back to port A of IC8255-PPI in mode-0.
Control word- 83H
Port Address of Control Register- FFFE
Port Address of Port A- FFF8
Port Address of Port B- FFFA
INSTRUMENT REQUIRED: 8086 Microprocessor Trainer Kit.
PROGRAM:

MEMORY LOCATION MACHINE CODE OPCODE OPERAND
0200 BA FE FF MOV DX,FFFE
0203 B083 MOV AL,83H
0205 EE OUT DX,AL
0206 BA FA FF LOOP1: MOV DX,FFFA
0209 EC IN AL,DX
020A F6 D0 NOT AL
020C BA F8 FF MOV DX,FFF8
020F EE OUT DX,AL
0210 75 F4 JMP LOOP1  
0212 F4 HLT  

DESCRIPTION:

To solve the given objective we have taken a Control Word to control the input.

83H is the memory location where the control word i.e. Input is placed or stored. Control word has a program which is used to make the Microprocessor Unit(MPU) understand the Input. Logic Controller Interface Card is used when we do not want to use 7-segment LED display.

To solve the given objective we have taken the following steps:

 

BIT PATTERN FOR CONTROL WORD

D7 D6 D5 D4 D3 D2 D1 D0
  1   0   0   0   0   0   1   1
  1. Move the data register (DX) to the memory location where the Control word i.e. 83H is stored, i.e. at FFFE.
  2. Move the control word 83H to the AL register.
  3. Complement the data of port B i.e. FFFA using NOT instruction and sent it back to port A i.e. FFF8 using a loop to JMP at port A.
  4. And finally Halt, the program.

INPUT:

MEMORY LOCATION VALUE
FFF8  (Address of Port A) 00
FFFA (Address of Port B) 03
FFFE (Address of Control Register) 83

OUTPUT:

MEMORY LOCATION VALUE
FFF8  (Address of Port A) FC
FFFA (Address of Port B) 03
FFFE (Address of Control Register) 83

RESULT: The complemented data from port address FFFA i.e. Port B has been transferred to port address FFF8 i.e. Port A using IC8255-PPI in mode-0.

FLOWCHART:

8255 microprocessor operating modes 8086 Microprocessor


Most Important Question for Exam

1. Primary function of memory is that the ______ should be able to rad from and write into register




Answer is C)
Microprocessor


2. To perfoarm any operations the Mp should identify the__________




Answer is D)
Register


3. The Microprocessor places__________address on the address bus




Answer is B)
16 bit

4. The Microprocessor places 16 bit address on the add lines from the address by__________register should be selected




Answer is C)
One

5. The _________of memory chip will identify and select the register for the EPROM




Answer is D)
Internal Decoder

6. Microprocessor provides signal like ______to indicate the read operation




Answer is B)
MCMR

7. To interface memory with the Microprocesor connect registe the lines of the address bus must be added to address lines of the _______chip.




Answer is D)
Memory

8. The remaining address line of ______bus is decoded to generate chip select signal




Answer is B)
Address

9. _______signal is generate by combie RD and WR with IO/M.




Answer is D)
Control

10. Memory is an integrated part of a __________ system




Answer is C)
Micro Computer

11. __________has certain signal requirements write into read from its registers




Answer is B)
Memory

12. The primary function of the________is to accept data from I/P devices




Answer is C)
Microprocessor

13. _________signal prevent the microprocessor from reading the same data more than one




Answer is C)
Handshaking

14. Bits in IRR interrupt are________




Answer is C)
Set

15. ________general interrupt signal to microprocessor and receive acknowledge




Answer is C)
Control Logic

16. The _____ pin is used to select direct command word




Answer is D)
A0

17. The_______is used to connect more Microprocessor




Answer is C)
Cascade

18. CS connect the output of ___________




Answer is C)
Decoder

19. In which year 8086 introduced?




Answer is B)
1978

20. Explain for HMOS technology____________




Answer is A)
High performance metal oxide semiconductor

21. 8086 and 8088 contains__________transistor




Answer is D)
29000

22. What is DEN?




Answer is B)
Deta Enable

23. In 8086 the overflow flag is set when___________




Answer is C)
Signed numbers go out of their range after an arithmetic operation

24. In 8086 Microprocessor one of the following statement is not true?




Answer is C)
Coprocessor is interfaced in min mode

25. Access time is faster for__________




Answer is C)
SRAM

26. Which of the following is not a basic element within the Microprocosser?




Answer is D)
Microcontrolle

27. Which method bypass the CPU for certain types of data transfer?




Answer is A)
Direct memory access(DMA)

28. Which is not an operand?




Answer is A)
Assembler

29. A 20 bit address bus can locate_________




Answer is B)
1,048,576 locations

30. Which of the following is not an arithmetic insturction?




Answer is A)
ROL (rotate left)

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