Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

8255 is not functioning properly

OmaerFaruq

Newbie
Newbie level 1
Joined
Jun 12, 2024
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
16
I have interfaced 82c55a with 8086. PortA (Mode 0) is defined as input and PotB (Mode 0) and PortC are defined as output. I have read PortA and send it to PortB. As well as, PC0 and and PC1 are set by BSR command. But it is not working. I have attached the Proteus file. The assembly code is provided with the internal assembler. I have also added the code below.
Code:

Code:
DATA SEGMENT                       
 PORTA          EQU 00H;0000 0000
 PORTB          EQU 02H;0000 0010
 PORTC          EQU 04H;0000 0100
 CWR            EQU 06H;0000 0110
DATA ENDS

CODE SEGMENT
        ASSUME CS:CODE,DS:DATA
        MOV     AX,DATA
        MOV     DS, AX
  
START:
        MOV     AL, 90H     ;1001 1000-->I/0,MA1,MA2,PA I/O,PCUp I/O, MB, PB I/0, PCl I/O
        OUT     CWR, AL
      
        MOV     AL, 01H     ;0000 0001 BSR command PC0
        OUT     CWR, AL
  
        MOV     AL, 03H     ;0000 0011 BSR command PC1
        OUT     CWR, AL
  
XX:           
        IN      AL,PORTA
        OUT     PORTB,AL
        JMP     XX

CODE ENDS
END START
 

Attachments

  • 8255 Class Demonstration.zip
    25.1 KB · Views: 46
  • 8255 Class Demonstration.PDF
    24.3 KB · Views: 42
Last edited:

LaTeX Commands Quick-Menu:

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top