
Applications Information
(Continued)
SAMPLE PROGRAM FOR ADC0844— INS8039 INTERFACE
CONVERTING TWO RATIOMETRIC, DIFFERENTIAL SIGNALS
(Continued)
0054
0056
0057
0059
005A
32 53
81
89 01
A0
83
JB1
MOVX
ORL
MOV
RET
LOOP
A,
@
R1
P1,&01H
@
R0,A
;IF INTR = 1 GOTO LOOP
;IF INTR = 0 INPUT A/D DATA
;CLEAR THE A/D CHIP SELECT
;STORE THE A/D DATA
;RETURN TO MAIN PROGRAM
SAMPLE PROGRAM FOR ADC0848— NSC800 INTERFACE
0008
000F
001F
3C00
NCONV
DEL
CS
ADDTA
EQU
EQU
EQU
EQU
16
15
1FH
003CH
;DELAY 50 μsec CONVERSION
;THE BOARD ADDRESS
;START OF RAM FOR A/D
;DATA
;MUX DATA
0000'
0004'
0008'
000A'
000C'
000F'
0012'
08 09 0A 0B
0C 0D 0E 0F
0E 1F
06 16
21 0000'
11 003C
ED A3
MUXDTA:
DB
DB
LD
LD
LD
LD
OUTI
08H,09H,0AH,0BH
0CH,0DH,0EH,0FH
C,CS
B,NCONV
HL,MUXDTA
DE,ADDTA
START:
STCONV:
;LOAD A/D’S MUX DATA
;AND START A CONVERSION
;HL=RAM ADDRESS FOR THE
;A/D DATA
0014'
EB
EX
DE,HL
0015'
0017'
0018'
001B'
3E 0F
3D
C2 0013'
ED A2
LD
DEC
JP
INI
A,DEL
A
NZ,WAIT
WAIT:
;WAIT 50 μsec FOR THE
;CONVERSION TO FINISH
;STORE THE A/D’S DATA
;CONVERTED ALL INPUTS
001D'
001E'
EB
C2 000E'
EX
JP
DE,HL
NZ,STCONV
;IF NOT GOTO STCONV
END
Note 14:
This routine sequentially programs the MUX data latch in the signal-ended mode. For CH1-CH8 a conversion is started, then a 50 μs wait for the A/D to
complete a conversion and the data is stored at address ADDTA for CH1, ADDTA + 1 for CH2, etc.
I/O Interface to NSC800
DS005016-28
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17