ADCTRIG                                                                                                       PAGE 1

                       1    ;======================================================================
                       2    ;
                       3    ; Author        : ADI - Apps
                       4    ;
                       5    ; Date          : Sept. '99
                       6    ;
                       7    ; File          : adctrig.asm
                       8    ;
                       9    ; Description   : Flash led an initial rate of 100ms
                      10    ;                 Pressing INTO triggers single conversion
                      11    ;                 The ADC result is written to external memory
                      12    ;                 The delay rate is increased
                      13    ;                 The program waits for the next INTO to repeat the 
                      14    ;                 above sequence
                      15    ;
                      16    ;======================================================================
                      17    ;       
                      18    $MOD824                                 ; Use ADuC824 predefined Symbols
                      19    
  0000                20    FLAG    EQU     00H                     ; Define Bit
                      21    
----                  22    CSEG                                    ; Defines the following as a segment of code
                      23    
0000                  24    ORG     0000H                           ; Load Code at '0'      
                      25    
0000 020057           26                    JMP     MAIN            ; Jump to MAIN
                      27    
                      28    ;======================================================================
                      29    
0003                  30    ORG 0003h                               ; (INT0 ISR)
0003 F5F0             31                    MOV     B,A             ; Copy A (sets delay)
0005 04               32                    INC     A               ; Increment delay
                      33    
0006 75D122           34                    MOV     ADCMODE,#22H    ; INITIATE A MAIN ADC SINGLE CONVERSION
                      35    
0009 30DFFD           36                    JNB     RDY0,$          ; Wait for conversion results
                      37                                            
                      38                                            ; Write ADC Result H/M/L to ext. memory
000C 900000           39                    MOV     DPTR, #00H      ; DPTR=00
000F E5D9             40                    MOV     A,ADC0L         ; read ADC low byte 
0011 F0               41                    MOVX    @DPTR,A         ; write low byte to ext memory
0012 A3               42                    INC     DPTR            ; DPTR=01
0013 E5DA             43                    MOV     A,ADC0M         ; read ADC Middle byte 
0015 F0               44                    MOVX    @DPTR,A         ; write Middle byte to ext memory
0016 A3               45                    INC     DPTR            ; DPTR=02
0017 E5DB             46                    MOV     A,ADC0H         ; read ADC High byte 
0019 F0               47                    MOVX    @DPTR,A         ; write low High byte to ext memory
001A A3               48                    INC     DPTR
                      49    
001B E5F0             50                    MOV     A,B             ; Restore A (sets delay)
001D 04               51                    INC     A               ; Increment delay
                      52    
001E 32               53                    RETI                    ; Return from Interrupt
                      54    
                      55    ;======================================================================
                      56    
                      57    
004B                  58    ORG 004Bh                               ; Subroutines
ADCTRIG                                                                                                       PAGE 2

                      59    
                      60    ;------------------------------------------------------------------
                      61    
004B                  62    DELAY:                                  ; Delays by 100ms * A
                      63    
004B F8               64                    MOV     R0,A            ; Acc holds delay variable
004C 7919             65     DLY0:          MOV     R1,#019h        ; Set up delay loop0
004E 7AFE             66     DLY1:          MOV     R2,#0FEh        ; Set up delay loop1
0050 DAFE             67                    DJNZ    R2,$            ; Dec R2 & Jump here until R2 is 0
0052 D9FA             68                    DJNZ    R1,DLY1         ; Dec R1 & Jump DLY1 until R1 is 0
0054 D8F6             69                    DJNZ    R0,DLY0         ; Dec R0 & Jump DLY0 until R0 is 0
0056 22               70                    RET                     ; Return from subroutine
                      71    
                      72    ;======================================================================
                      73    
0057                  74    MAIN:                                   ; (main program)
                      75    
                      76                                            ; Configure ADC
0057 75D120           77                    MOV     ADCMODE,#20H    ; ENABLE MAIN ADC; Mode- Power down 
005A 75D247           78                    MOV     ADC0CON,#47H    ; 24 BITS
                      79                                            ; USE EXTERNAL REFERENCE
                      80                                            ; AIN1-AIN2 
                      81                                            ; BIPOLAR MODE
                      82                                            ; RANGE = +/-2.56V 
                      83    
005D D288             84                    SETB    IT0             ; INT0 edge triggered
005F D2AF             85                    SETB    EA              ; enable inturrupts
0061 D2A8             86                    SETB    EX0             ; enable INT0
                      87            
0063 C200             88                    CLR     FLAG            ; Clear Bit defined as FLAG
                      89            
0065 7401             90                    MOV     A,#01H          ; Initialize A -> 1
0067 B2B4             91    BLINK:          CPL     P3.4            ; blink LED using compliment instruction
0069 114B             92                    CALL    DELAY           ; Jump to subroutine DELAY
006B 3000F9           93                    JNB     FLAG,BLINK      ; If FLAG is still cleared the jump to Blink
                      94    
                      95    END
                      96    
                      97            
                      98    

VERSION 1.2h ASSEMBLY COMPLETE, 0 ERRORS FOUND
ADCTRIG                                                                                                       PAGE 3

ADC0CON. . . . . . . . . . . . .  D ADDR  00D2H  PREDEFINED  
ADC0H. . . . . . . . . . . . . .  D ADDR  00DBH  PREDEFINED  
ADC0L. . . . . . . . . . . . . .  D ADDR  00D9H  PREDEFINED  
ADC0M. . . . . . . . . . . . . .  D ADDR  00DAH  PREDEFINED  
ADCMODE. . . . . . . . . . . . .  D ADDR  00D1H  PREDEFINED  
B. . . . . . . . . . . . . . . .  D ADDR  00F0H  PREDEFINED  
BLINK. . . . . . . . . . . . . .  C ADDR  0067H  
DELAY. . . . . . . . . . . . . .  C ADDR  004BH  
DLY0 . . . . . . . . . . . . . .  C ADDR  004CH  
DLY1 . . . . . . . . . . . . . .  C ADDR  004EH  
EA . . . . . . . . . . . . . . .  B ADDR  00AFH  PREDEFINED  
EX0. . . . . . . . . . . . . . .  B ADDR  00A8H  PREDEFINED  
FLAG . . . . . . . . . . . . . .    NUMB  0000H  
IT0. . . . . . . . . . . . . . .  B ADDR  0088H  PREDEFINED  
MAIN . . . . . . . . . . . . . .  C ADDR  0057H  
P3 . . . . . . . . . . . . . . .  D ADDR  00B0H  PREDEFINED  
RDY0 . . . . . . . . . . . . . .  B ADDR  00DFH  PREDEFINED