i2cmem.sdi

来自「代码保护功能处于持续发展中。Microchip 承诺将不断改进产品的代码保护功能」· SDI 代码 · 共 204 行

,,,;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
,,,;
,,,;       I2CMEM.ASM              MPB     7-1-06
,,,;
,,,;       Test program for 24AA128 I2C 16k byte serial
,,,;       memory with P16F877A (4MHz XT)
,,,;       Demonstrates single byte write and read
,,,;       with 10-bit address.
,,,;
,,,;       Write data from                 0x20
,,,;       High address                    0x21
,,,;       Low address                     0x22
,,,;       Read data back to               0x23
,,,;
,,,;       Version: Final
,,,;
,,,;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
,,,
,,,        PROCESSOR 16F877A
00002007,3FF1,,        __CONFIG 3FF1
,,,        INCLUDE "P16F877A.INC"
,,,
,,,; Data, address & control registers ;;;;;;;;;;;;;;;;;;;;
,,,
,,,SenReg  EQU     0x20            ; Send data store
,,,HiReg   EQU     0x21            ; High address store
,,,LoReg   EQU     0x22            ; Low address store
,,,RecReg  EQU     0x23            ; Receive data store
,,,ConReg  EQU     0x24            ; Control byte store
,,,Temp    EQU     0x25            ; Scratchpad location
,,,
,,,;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
,,,
,,,        ORG     0               ; Program start address
,,,
00000000,01A0,,        CLRF    SenReg          ; Zeroise data
00000001,01A1,,        CLRF    HiReg           ; Zeroise high address
00000002,01A2,,        CLRF    LoReg           ; Zeroise low address
00000003,2872,,        GOTO    begin           ; jump to main program
,,,
,,,;--------------------------------------------------------
,,,; SUBROUTINES ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
,,,
,,,; Wait for interrupt flag SSPIF for send/recive done ...
,,,
00000004,0000,wint,wint    NOP                     ; BANKSEL has no address
00000005,1283 1303,,        BANKSEL PIR1            ; Select bank
00000007,118C,,        BCF     PIR1,SSPIF      ; reset interrupt flag
00000008,0000,win,win     NOP
00000009,1D8C,,        BTFSS   PIR1,SSPIF      ; wait for..
0000000A,2808,,        GOTO    win             ; ..transmit done
0000000B,0008,,        RETURN                  ; done
,,,
,,,
,,,; Send a byte ....................................
,,,
0000000C,0000,send,send    NOP                     ; Select..
0000000D,1283 1303,,        BANKSEL SSPBUF          ; .. bank
0000000F,0093,,        MOVWF   SSPBUF          ; Send address/data
00000010,2004,,        CALL    wint            ; Wait until sent
00000011,0008,,        RETURN                  ; done
,,,
,,,;--------------------------------------------------------
,,,; Routines to send start, control, address, data, stop ..
,,,;........................................................
,,,
00000012,0000,sencon,sencon  NOP                     ; GENERATE START BIT
00000013,1283 1303,,        BANKSEL PIR1
00000015,118C,,        BCF     PIR1,SSPIF      ; Clear interrupt flag
00000016,1683 1303,,        BANKSEL SSPCON2         ; select register page
00000018,1711,,        BSF     SSPCON2,ACKSTAT ; Set acknowledge flag
00000019,1411,,        BSF     SSPCON2,SEN     ; Generate start bit
0000001A,2004,,        CALL    wint            ; wait till done
0000001B,0824,,        MOVF    ConReg,W        ; SEND CONTROL BYTE
0000001C,200C,,        CALL    send            ; Memory ID & chip address
0000001D,0008,,        RETURN                  ; done
,,,
,,,;........................................................
,,,
0000001E,0000,senadd,senadd  NOP
0000001F,1283 1303,,        BANKSEL SSPCON          ; SEND ADDRESS BYTES
00000021,0821,,        MOVF    HiReg,W         ; load address high byte
00000022,200C,,        CALL    send            ; and send
00000023,0822,,        MOVF    LoReg,W         ; load address low byte
00000024,200C,,        CALL    send            ; and send
00000025,0008,,        RETURN
,,,
,,,;........................................................
,,,
00000026,0820,sendat,sendat  MOVF    SenReg,W        ; Load data
00000027,200C,,        CALL    send            ; and send
00000028,0008,,        RETURN                  ; done
,,,
,,,;........................................................
,,,
00000029,0000,senstop,senstop NOP
0000002A,1683 1303,,        BANKSEL SSPCON2         ; GENERATE STOP BIT
0000002C,1511,,        BSF     SSPCON2,PEN     ; Generate stop bit
0000002D,2004,,        CALL    wint            ; wait till done
0000002E,0008,,        RETURN                  ; done
,,,
,,,;........................................................
,,,
0000002F,0000,senack,senack  NOP
00000030,1683 1303,,        BANKSEL SSPCON2
00000032,1691,,        BSF     SSPCON2,ACKDT   ; Set ack. bit high
00000033,1611,,        BSF     SSPCON2,ACKEN   ; Initiate ack.sequence
00000034,2004,,        CALL    wint            ; Wait for ack. done
00000035,0008,,        RETURN                  ; done
,,,
,,,;........................................................
,,,
00000036,0000,wait,wait    NOP
00000037,1283 1303,,        BANKSEL TMR0            ; WAIT FOR WRITE DONE
00000039,309C,,        MOVLW   d'156'          ; Set starting value
0000003A,0081,,        MOVWF   TMR0            ; and load into timer
0000003B,1283 1303,,        BANKSEL INTCON          ; 64 x 156us = 10ms
0000003D,110B,,        BCF     INTCON,T0IF     ; Reset timer out flag
0000003E,1D0B,wem,wem     BTFSS   INTCON,T0IF     ; Wait 10ms
0000003F,283E,,        GOTO    wem             ; for timeout
00000040,1283 1303,,        BANKSEL TMR0            ; default bank
00000042,0008,,        RETURN                  ; Byte write done....
,,,
,,,;--------------------------------------------------------
,,,; Initialisation sequence ..............................
,,,
00000043,0000,init,init    NOP
00000044,1683 1303,,        BANKSEL SSPCON2         ;
00000046,3060,,        MOVLW   b'01100000'     ; Set ACKSTAT,ACKDT bits
00000047,0091,,        MOVWF   SSPCON2         ; Reset SEN,ACK bits
00000048,3080,,        MOVLW   b'10000000'     ;
00000049,0094,,        MOVWF   SSPSTAT         ; Speed & signal levels
0000004A,3013,,        MOVLW   0x13            ; Clock = 50kHz
0000004B,0093,,        MOVWF   SSPADD          ; Load baud rate count-1
0000004C,1283 1303,,        BANKSEL SSPCON          ;
0000004E,3028,,        MOVLW   b'00101000'     ;
0000004F,0094,,        MOVWF   SSPCON          ; Set mode & enable
00000050,118C,,        BCF     PIR1,SSPIF      ; clear interrupt flag
,,,
,,,; Initialise TIMER0 for write delay ...............
,,,
00000051,1683 1303,,        BANKSEL OPTION_REG      ;
00000053,30C5,,        MOVLW   B'11000101'     ; TIMER0 setup code
00000054,0081,,        MOVWF   OPTION_REG      ; Internal clock,1/64
00000055,1283 1303,,        BANKSEL TMR0
00000057,0008,,        RETURN
,,,
,,,;--------------------------------------------------------
,,,; Write a test byte to given address ................
,,,
00000058,30A0,writeb,writeb  MOVLW   0xA0            ; Control byte for WRITE
00000059,00A4,,        MOVWF   ConReg          ;
0000005A,2012,,        CALL    sencon          ; Send control byte
0000005B,201E,,        CALL    senadd          ; Send address bytes
0000005C,2026,,        CALL    sendat          ; Send data byte
0000005D,2029,,        CALL    senstop         ; Send stop bit
0000005E,2036,,        CALL    wait            ; Wait 10ms for write
0000005F,0008,,        RETURN
,,,
,,,;--------------------------------------------------------
,,,; Read the byte from given address ...................
,,,
00000060,30A0,readb,readb   MOVLW   0xA0            ; Control byte to WRITE
00000061,00A4,,        MOVWF   ConReg          ; address to memory
00000062,2012,,        CALL    sencon          ; Send control byte
00000063,201E,,        CALL    senadd          ; Send address bytes
00000064,2029,,        CALL    senstop         ; Stop
,,,
00000065,30A1,,        MOVLW   0xA1            ; Control byte to READ
00000066,00A4,,        MOVWF   ConReg          ; data from memory
00000067,2012,,        CALL    sencon          ; Send control byte
00000068,1683 1303,,        BANKSEL SSPCON2
0000006A,1591,,        BSF     SSPCON2,RCEN    ; Enable receive mode
0000006B,1C14,war,war     BTFSS   SSPSTAT,BF      ; Check ...
0000006C,286B,,        GOTO    war             ; for read done
0000006D,202F,,        CALL    senack          ; send NOT acknowledge
0000006E,2029,,        CALL    senstop         ; send stop bit
,,,
0000006F,0813,,        MOVF    SSPBUF,W        ; Read receive buffer
00000070,00A3,,        MOVWF   RecReg          ; and store it
00000071,0008,,        RETURN
,,,
,,,
,,,; MAIN PROGRAM  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
,,,
00000072,2043,begin,begin   CALL    init            ; Initialise for I2C
00000073,2058,next,next    CALL    writeb          ; write the test byte
00000074,2060,,        CALL    readb           ; and read it back
00000075,0AA0,,        INCF    SenReg          ; next data
00000076,0AA2,,        INCF    LoReg           ; next location
00000077,1D03,,        BTFSS   STATUS,Z        ; end of memory block?
00000078,2873,,        GOTO    next            ; no, next location
00000079,0AA1,,        INCF    HiReg           ; next block
,,,
0000007A,0821,,        MOVF    HiReg,W         ; copy high address byte
0000007B,00A5,,        MOVWF   Temp            ; store it
0000007C,3040,,        MOVLW   0x40            ; Last block = 3F
0000007D,02A5,,        SUBWF   Temp            ; Compare
0000007E,1D03,,        BTFSS   STATUS,Z        ; Finish if block = 40xx
0000007F,2873,,        GOTO    next            ; next memory block..
00000080,0063,,        SLEEP                   ; .. unless done
,,,
,,,        END     ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;