i2cmstr.lst

大量ADuc831的程序员代码

I2CMSTR                                                                                                       PAGE 1

                       1    ;======================================================================
                       2    ;
                       3    ; Author        : ADI - Apps              www.analog.com/MicroConverter
                       4    ;
                       5    ; Date          : May 2002
                       6    ;
                       7    ; File          : i2Cmstr.asm
                       8    ;
                       9    ; Hardware      : ADuC831
                      10    ;
                      11    ; Description   : Code for a master in an I2C system. This code will
                      12    ;               continuously receive and transmit a byte over the I2C
                      13    ;               interface, then send the received byte out the UART,
                      14    ;               then check if a character had been entered in the UART,
                      15    ;               if so, it will send the ASCII value of the character
                      16    ;               entered to the slave, the next time it transmits a byte.
                      17    ;
                      18    ; Reference     : Tech Note, uC001: "MicroConverter I2C Compatible
                      19    ;               Interface" find it at www.analog.com/microconverter
                      20    
                      21    ;
                      22    ;======================================================================
                      23    
                      24    $MOD831
                      25    
                      26    ;____________________________________________________________________
                      27                                       ; DEFINE VARIABLES IN INTERNAL RAM
                      28    
  0030                29    BITCNT          DATA    30h     ; bit counter for I2C routines
  0031                30    SLAVEADD        DATA    31h     ; slave address for I2C routines
  0032                31    INPUT           DATA    32h     ; data recieved from the slave
  0033                32    OUTPUT          DATA    33h     ; data to be transmitted to slave
                      33    
  0000                34    NOACK           BIT     00h     ; I2C no acknowledge flag
  0000                35    ERR             BIT     00h     ; I2C error flag
                      36    
  00B4                37    LED             EQU     P3.4
                      38    
                      39    
                      40    
                      41    ;____________________________________________________________________
                      42                                                      ; BEGINNING OF CODE
----                  43    CSEG
0000                  44    ORG 0000h
0000 020060           45            JMP MAIN
                      46    
                      47    
                      48    ;____________________________________________________________________
                      49                                                               ; INT0 ISR
0003                  50    ORG 0003h
0003 0533             51            INC     OUTPUT
0005 32               52            RETI
                      53     
                      54    ;____________________________________________________________________
                      55                                                           ; MAIN PROGRAM
0060                  56    ORG 0060h
0060                  57    MAIN:
                      58    
I2CMSTR                                                                                                       PAGE 2

0060 759E85           59            MOV T3CON,#085h
0063 759D08           60            MOV T3FD,#08h
0066 759852           61            MOV SCON,#52h
                      62    
                      63    ; configure & enable interrupts
0069 D2A8             64            SETB    EX0             ; enable INT0
006B D288             65            SETB    IT0             ; INT0 edge triggered
006D D2AF             66            SETB    EA              ; allow all the interrupts
                      67    
                      68    ; initialise settings
006F 753188           69            MOV     SLAVEADD,#88H   ; clear RW bit
0072 75E8A8           70            MOV     I2CCON,#0A8h    ; sets SDATA & SCLOCK, and
                      71                                    ; selects master mode
0075 753300           72            MOV     OUTPUT,#0       ; TX 0 as default
0078 C200             73            CLR     NOACK
007A C200             74            CLR     ERR
                      75    
007C                  76    RXTXLOOP:    
                      77    ; code for a read mode ( master recieves one byte from slave )
007C 1200C6           78            CALL    RCVDATA         ; sends start bit
                      79                                    ; sends address byte
                      80                                    ; checks acknowledge
                      81                                    ; receives byte into ACC
                      82                                    ; checks ACK
                      83                                    ; sends stop bit
                      84    
                      85    ; code for write mode ( master transmits one byte to slave )
007F 1200AD           86            CALL    SENDDATA        ; sends start bit
                      87                                    ; sends address byte
                      88                                    ; checks acknowledge
                      89                                    ; transmits ACC
                      90                                    ; checks ACK
                      91                                    ; sends stop bit
                      92    
                      93    ; Check for Error message
0082 200008           94            JB    ERR,SENDERR         ; if error, send error message
                      95    
                      96    ; Transmit received byte (INPUT) up UART to PC (hyperterminal)
0085 E532             97            MOV     A,INPUT           ; put value received into ACC
0087 120152           98            CALL    SENDVAL           ; send value received out the UART
008A 020092           99            JMP     SKIP
                     100    
008D                 101    SENDERR:
008D 120138          102            CALL    ERROR             ; send error message out the UART
0090 C200            103            CLR     ERR               ; clear error flag
                     104    
0092                 105    SKIP:
0092 740A            106            MOV     A,#10             ; send LF+CR
0094 12013E          107            CALL    SENDCHAR
0097 740D            108            MOV     A,#13
0099 12013E          109            CALL    SENDCHAR
                     110    
                     111    ; Toggle LED (1s delay so that LED can be seen toggle)
009C 740A            112            MOV     A, #10
009E 12012C          113            CALL    DELAY
00A1 B2B4            114            CPL     LED
                     115    
                     116    ; Check for new OUTPUT
I2CMSTR                                                                                                       PAGE 3

00A3 3098D6          117            JNB     RI, RXTXLOOP      ; repeat (unless UART data received)
                     118    
                     119    ; If UART data received, then save to OUTPUT
00A6 859933          120            MOV     OUTPUT,SBUF       ; update OUTPUT byte to new value
00A9 C298            121            CLR     RI                ; must clear RI
00AB 80CF            122            JMP     RXTXLOOP          ; back to main loop
                     123    
                     124    
                     125    ;====================================================================
                     126    ;                             SUBROUTINES
                     127    ;====================================================================
                     128    
                     129    ;____________________________________________________________________
                     130                                                               ; SENDDATA
                     131    ; Send all the sequence to the slave (slave address + data (OUTPUT))
                     132    
00AD                 133    SENDDATA:
                     134            ; send start bit
00AD 1200E3          135            CALL    STARTBIT        ; acquire bus and send slave address
                     136    
                     137            ; send slave address
00B0 E531            138            MOV     A, SLAVEADD
00B2 1200F5          139            CALL    SENDBYTE        ; sets NOACK if NACK received
                     140    
00B5 200005          141            JB      NOACK, STOPSEND ; if no acknowledge send stop
                     142    
                     143            ; send OUTPUT byte
00B8 E533            144            MOV     A, OUTPUT
00BA 1200F5          145            CALL    SENDBYTE        ; sets NOACK if NACK received
                     146    
00BD                 147    STOPSEND:  
00BD 1200EC          148            CALL    STOPBIT         ; sends stop bit
00C0 300002          149            JNB     NOACK, SENDRET  ; if slave sends NACK send error
00C3 D200            150            SETB    ERR             ; sets the error flag
00C5                 151    SENDRET:
00C5 22              152            RET
                     153     
                     154    ;____________________________________________________________________
                     155                                                                ; RCVDATA
                     156    ; receives one or more bytes of data from an I2C slave device.
                     157    
00C6                 158    RCVDATA:   
00C6 0531            159            INC     SLAVEADD        ; Set RW for reception
                     160    
                     161            ; send start bit
00C8 1200E3          162            CALL    STARTBIT        ; acquire bus and send slave address
                     163    
                     164            ; send slave address
00CB E531            165            MOV     A, SLAVEADD
00CD 1200F5          166            CALL    SENDBYTE        ; sets NOACK if NACK received
                     167    
00D0 1531            168            DEC     SLAVEADD        ; returns SLAVEADD to 88h (after INC)
                     169    
00D2 200005          170            JB      NOACK, STOPRCV  ; Check for slave not responding.
00D5 120112          171            CALL    RCVBYTE         ; Receive next data byte.
00D8 F532            172            MOV     INPUT,A         ; Save data byte in buffer.
                     173    
00DA                 174    STOPRCV:
I2CMSTR                                                                                                       PAGE 4

00DA 1200EC          175            CALL    STOPBIT
00DD 300002          176            JNB     NOACK, RCVRET   ; if slave sends NACK send error
00E0 D200            177            SETB    ERR             ; sets the error flag
00E2                 178    RCVRET:
00E2 22              179            RET