i2cslave.lst

于ADuC812的智能无功补偿控制器的研制 一种眼科B型超声诊断议 SL11R单片机外部存储器扩展 单片机复位电路...支持键盘双击事件的C程序设计! 一些源程序 FrankLin C51 库函数的一

I2CSLAVE                                                                                                      PAGE 1

                       1    ;======================================================================
                       2    ;
                       3    ; Author        : ADI - Apps              www.analog.com/MicroConverter
                       4    ;
                       5    ; Date          : May 2002
                       6    ;
                       7    ; File          : i2cslave.asm
                       8    ;
                       9    ; Hardware      : ADuC814
                      10    ;
                      11    ; Description   : Code for a slave 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    $MOD814
                      24    
                      25    ;____________________________________________________________________
                      26                                       ; DEFINE VARIABLES IN INTERNAL RAM
                      27    
  0030                28    BYTECNT         DATA    30h       ; byte counter for I2C routines
  0031                29    INPUT           DATA    31h       ; data recieved from master
  0032                30    OUTPUT          DATA    32h       ; data to be transmitted to master
                      31    
  0000                32    GO              BIT     00h       ; flag to wait for interrupts
  0001                33    FIRST           BIT     01h       ; flag to indicate first receive Int
                      34    
  00B4                35    LED             EQU     P3.4      ; P3.4 drives the LED on eval board
                      36    
                      37    ;____________________________________________________________________
                      38                                                      ; BEGINNING OF CODE
----                  39    CSEG
0000                  40    ORG 0000h
0000 020060           41            JMP MAIN
                      42    ;____________________________________________________________________
                      43                                                               ; INT0 ISR
0003                  44    ORG 0003h
0003 0532             45            INC     OUTPUT
0005 32               46            RETI
                      47    ;____________________________________________________________________
                      48                                                                ; I2C ISR
003B                  49    ORG 003Bh  
                      50    
003B 20E90B           51          JB      I2CTX, SLAVE_TRANSMITTER
                      52    
003E                  53    SLAVE_RECEIVER:
003E 200110           54          JB      FIRST, ENDINT1  ; if first INT then wait for next int
0041 D200             55          SETB    GO              ; reception complete 
0043 859A31           56          MOV     INPUT, I2CDAT   ; store data received in INPUT
0046 020051           57          JMP     ENDINT1
                      58    
I2CSLAVE                                                                                                      PAGE 2

0049                  59    SLAVE_TRANSMITTER:
0049 D200             60          SETB    GO              ; transmission complete
004B 85329A           61          MOV     I2CDAT, OUTPUT  ; move data to be transmitted into I2CDAT
004E 020053           62          JMP     ENDINT2         ; Note: On the ADuC824/816 the read or
                      63                                  ;       write of I2CDAT register 
                      64                                  ;       automatically clears i2ci. If
                      65                                  ;       I2CI is cleared twice then the
                      66                                  ;       microconverter will hang.)
                      67    
0051                  68    ENDINT1:
0051 C2E8             69          CLR     I2CI            ; clear I2C interrupt bit (812 only)
0053                  70    ENDINT2:
0053 C201             71          CLR     FIRST           ; address has already been received
0055 32               72          RETI
                      73    
                      74    ;____________________________________________________________________
                      75                                                           ; MAIN PROGRAM
0060                  76    ORG 0060h
0060                  77    MAIN:
                      78    
                      79    
                      80    ; configure the UART ADuC812s
0060 75CBFF           81          MOV     RCAP2H,#0FFh   ; config UART for 9830baud
0063 75CAF9           82          MOV     RCAP2L,#-7     ; (close enough to 9600baud)
0066 75CDFF           83          MOV     TH2,#0FFh
0069 75CCF9           84          MOV     TL2,#-7
006C 759852           85          MOV     SCON,#52h
006F 75C834           86          MOV     T2CON,#34h
                      87    
                      88    ; configure pins for 812s
0072 759C01           89          MOV     CFG814,#01H
                      90    
                      91    ;configure and enable interrupts
                      92    ;      MOV     IE2,#01h       ; enable I2C interrupt
0075 75A901           93          MOV     IEIP2,#01h    ; enable I2C interrupt
0078 D2A8             94          SETB    EX0            ; enable INT0
007A D288             95          SETB    IT0            ; INT0 edge triggered
007C D2AF             96          SETB    EA             ; allow all the interrupts
                      97    
                      98    ;initialize settings
007E 759B44           99          MOV     I2CADD,#044h   ; slave address is 44h
0081 75E800          100          MOV     I2CCON,#00h    ; slave mode (default=>not necessary)
0084 C200            101          CLR     GO             ; clear flag to wait for interrupt
                     102                                 ; GO is set once data is TX'd or RX'd
0086 D201            103          SETB    FIRST          ; FIRST is cleared after receiving the
                     104                                 ; first SLAVE receiver interrupt
                     105    
0088 753200          106          MOV     OUTPUT,#0      ; first byte to be transmitted is 40h 
008B C2B4            107          CLR     LED
                     108    
008D                 109    WAITFORDATA:  
008D 3000FD          110          JNB     GO,$           ; ----- wait for i2c interrupt ------
                     111                                 ; If it is in receive mode, it will 
                     112                                 ; wait here for a second interrupt (as 
                     113                                 ; the first interrupt only contains the
                     114                                 ; slave address in I2CDAT).
                     115                                 ; In transmit mode the tranmission will
                     116                                 ; occur after the first interrupt.