Interfacing ADC and DAC to 8086.
1.Digital to Anolog converter.
Aim:
Program to generate following wave forms a. Ramp waveform b. Square waveform c. Step waveform d. Triangle waveform
Apparatus:
1. ADS-SDA-86-STA kit 2. 8255 Study card 3. Adapter, Keyboard, Cables, CRO Etc...
Procedure:
1. Connect 8086 kit PC using RS232 cable. 2. Connect Power supply to 8086 kit and 8255 interfacing kit(only blue( 5v) and black(0v) lines Power cable to power supply) 3. Connect 8255 to CN4 of 8086 using 26 pin bus. 4. Connect the CRO probe to JP3 of 8255 kit 5. Keep the DIP switch in 1 & 7 on (8086kit), open TALK, and go to options select target device as 8086 and Connect. 6. Change dip switch into 1 & 5on, once reset 8086 kit. 7. Go to file →Download hex file 8. G-5000(on system keyboard), we can observe the output on 8086 kit and CRO.
Program:
Ramp Wave Form Generation
.OUTPUT 2500AD CONTROL EQU FFC6H ;control port address for 8255 PORTA EQU FFC0H ;porta address for 8255 PORTB EQU FFC2H ;portb address for 8255 PORTC EQU FFC4H ;portc address for 8255 DSEG SEGMENT ORG 0000: 4000H MSG DB' Dac mode ',0h MSG1 DB 'Ramp wave output',0h DSEG ENDS CSEG SEGMENT ORG 0000 : 5000H ASSUME CS : CSEG, DS : DSEG START: MOV DX, CONTROL MOV AL, 80H ;initialise all ports as output OUT DX, AL ;ports ;displaying message on LCD Call far f800 : 4bb1h ;clear display Mov di, 80h ;display in upper line MOV SI, offset MSG CALL FAR f800 : 4FC0h ;display output routine MOV DI, C0H ;display in lower line MOV SI, OFFSET MSG1 CALL FAR F800 : 4FC0H ;display output routine ;ramp wave form generation MOV BL, 00H RAMP: MOV DX, PORTB MOV AL, BL ;increment the digital code OUT DX, AL ;and output it on to PORTB INC BL ;check to see if a NMI-INTR JNZ RAMP MOV BL, 00H JMP RAMP CSEGENDS END SQUARE WAVEFORM: DA00: MOV DX, PORTB MOV AL, 00H ;outport 00 for 0V level CALL OUTPUT MOV AL, 0FFH CALL OUTPUT JMP DA00 ;routine to output digital value OUTPUT: OUT DX, AL CALL DELAY RET DELAY: MOV CX,0FFH ;to vary the frequency alter the delay count LUP1: LOOP LUP1 RET STEP WAVEFORM: DA00: MOV DX, PORTB MOV AL, 00H ;outport 00 for 0V level CALL OUTPUT MOV AL, 7FH ;outport 7F for 2.5V level CALL OUTPUT MOV AL, FFH ;outport FF for 5V level CALL OUTPUT ;look for NMI-INTR if user JMP DA00 ;switch to ramp w/f generation ;routine to output digital value OUTPUT: OUT DX, AL MOV CX, FFH DELAY: LOOP DELAY RET TRIANGULAR WAVEFORM: DA00: MOV DX, PORTB MOV AL, 00H ;outport 00 for 0V level UP: CALL OUTPUT INC AL CMP AL, 00H JNZ UP MOV AL, 0FFH ;to change amplitude change count UP1: CALL OUTPUT DEC AL CMP AL, 0FFH JNZ UP1 JMP DA00 ;routine to output digital value OUTPUT: OUT DX, AL CALL DELAY RET DELAY: MOV CX, 07H ;to vary the frequency alter the delay count LUP1: LOOP LUP1 RET
Step waveform:
DA00: MOV DX, PORTB MOV AL, 00H ;outport 00 for 0V level CALL OUTPUT MOV AL, 7FH ;outport 7F for 2.5V level CALL OUTPUT MOV AL, FFH ;outport FF for 5V level CALL OUTPUT ;look for NMI-INTR if user JMP DA00 ;switch to ramp w/f generation ;routine to output digital value OUTPUT: OUT DX, AL MOV CX, FFH DELAY: LOOP DELAY RET
Triangular waveform:
DA00: MOV DX, PORTB
MOV AL, 00H ;outport 00 for 0V level
UP: CALL OUTPUT
INC AL
CMP AL, 00H
JNZ UP
MOV AL, 0FFH ;to change amplitude change count
UP1: CALL OUTPUT
DEC AL
CMP AL, 0FFH
JNZ UP1
JMP DA00
;routine to output digital value
OUTPUT: OUT DX, AL
CALL DELAY
RET
DELAY: MOV CX, 07H ;to vary the frequency alter the delay count
LUP1: LOOP LUP1
RET
Result:
The waveforms are generated by interfacing PPI to 8086 kit and observed on CRO.
2. Anolog to Digital converter.
Aim:
Write a program in ALP to establish Communication between two processors using 8251.
Apparatus:
1. ADS-SDA-86-STA kit 2. 8255 Study card 3. Adapter, Keyboard, Cables, Connecting Wires Etc...
Procedure:
1. Connect 8086 kit PC using RS232 cable. 2. Connect Power supply to 8086 kit and 8255 interfacing kit(only blue( 5v) and black(0v) lines Power cable to power supply) 3. Connect 8255 to CN4 of 8086 using 26 pin bus. 4. Keep the DIP switch in 1 & 7 on (8086kit), open TALK, and go to options select target device as 8086 and Connect. 5. Change dip switch into 1 & 5on, once reset 8086 kit. 6. Go to file →Download hex file 7. Keep the DIP switch in 1 & 7 on (8086kit) 8. G-5000(on kit keyboard), ‘ENTER CHANNEL NUMBER” displays on LCD display. 9. Type the channel number on kit keyboard and connect the connecting wire the particular channel and power supplies given to 8255 study card. Now observe the output on the 8086 kit
Program:
.OUTPUT 2500AD CONTROL EQU FFC6H ;control port address for 8255 PORTA EQU FFC0H ;porta address for 8255 PORTB EQU FFC2H ;portb address for 8255 PORTC EQU FFC4H ;portc address for 8255 KWAD EQU F800 : 4EEDH DBDTA EQUF800 : 4F1FH DSEG SEGMENT ORG 0000 : 4000H MSG DB 'Enter channel No',0h DSEG ENDS CSEG SEGMENT ASSUME CS : CSEG, DS : DSEG ORG 0000 : 5000H ;displaying message on LCD Callfar f800 : 4bb1h ;clear display movdi, 80h ;display in upper line MOV SI, offset MSG ; CALLFAR f800 : 4FC0h ;display output routine MOV AX, 0000H MOV DS, AX ;AD00: CALL FAR KWAD ;get key for channel selection MOV CX, SI MOV AL, 90H ;control word for PPI MOV DX, CONTROL OUT DX, AL ;portA->i/p port,portB->o/p port ;portC->o/p port. AD00: MOV AL, CL ;output channel number MOV DX, PORTC OUT DX, AL ;start conversion MOV AL, 0FH ;PC7 (START/ALE) set MOV DX, CONTROL OUT DX, AL PUSH CX MOV CX, 3FFFH DEL1: LOOP DEL1 POP CX MOV AL, 0EH ;PC7 reset MOV DX, CONTROL OUT DX, AL ;look for EOC MOV AL, 0CH ;reset PC6 to read EOC OUT DX, AL AD01: MOV DX, PORTA IN AL, DX ;poll the EOC line which AND AL, 80H ;is connected to PA7 line CMP AL, 80H JNZ AD01 ;if EOC (PA7) is high read the digital value otherwise again check for EOC (PA7) line MOV AL, 0DH ;set OE (PC6) to read value MOV DX, CONTROL OUT DX, AL ;before reading data from ADC set PC6 line MOV DX, PORTA IN AL, DX ;read digital value MOV AH, 00H MOV SI, AX PUSH CX CALL FAR DBDTA ;display digital value POP CX JMP AD00 CSEG ENDS END
Result:
Analog to Digital Conversion using 8255 is studied is Studied And The Output is Verified
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UpdatedOct 25, 2014
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Views20,372
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