tl.sdi

步进电机设计

,,,1            LIST    p=16F84 ; PIC16F844 is the target processor
,,,2
,,,3            #include "P16F84.INC" ; Include header file
,,,4
,,,5            CBLOCK 0x10   ; Temporary storage
,,,6               state
,,,7               l1,l2
,,,8            ENDC
,,,9
0000,,0,0            org     0               ; Start up vector.
0000,  2805,1,1            goto    setports        ; Go to start up code.
,,,2
0004,,3,3            org     4               ; Interrupt vector.
0004,  0061,4,4 halt       goto    halt            ; Sit in endless loop and do nothing.
,,,5
0005,  0103,6,6 setports   clrw                    ; Zero in to W.
0006,  0085,7,7            movwf   PORTA           ; Ensure PORTA is zero before we enable it.
0007,  0086,8,8            movwf   PORTB           ; Ensure PORTB is zero before we enable it.
0008,  1683,9,9            bsf     STATUS,RP0      ; Select Bank 1
0009,  0103,0,0            clrw                    ; Mask for all bits as outputs.
000A,  0086,1,1            movwf   TRISB           ; Set TRISB register.
000B,  1283,2,2            bcf     STATUS,RP0      ; Reselect Bank 0.
,,,3
000C,  0103,4,4 initialise clrw                    ; Initial state.
000D,  0090,5,5            movwf   state           ; Set it.
,,,6
000E,  2015,7,7 loop       call    getmask         ; Convert state to bitmask.
000F,  0086,8,8            movwf   PORTB           ; Write it to port.
0010,  0A10,9,9            incf    state,W         ; Increment state in to W.
0011,  3904,0,0            andlw   0x04            ; Wrap it around.
0012,  0090,1,1            movwf   state           ; Put it back in to memory.
0013,  201B,2,2            call    wait            ; Wait :-)
0014,  280E,3,3            goto    loop            ; And loop :-)
,,,4
,,,5            ; Function to return bitmask for output port for current state.
,,,6            ; The top nibble contains the bits for one set of lights and the
,,,7            ; lower nibble the bits for the other set. Bit 1 is red, 2 is amber
,,,8            ; and bit three is green. Bit four is not used.
0015,  0810,9,9 getmask    movf    state,W         ; Get state in to W.
0016,  0782,0,0            addwf   PCL,F           ; Add offset in W to PCL to calc. goto.
0017,  3441,1,1            retlw   0x41            ; state==0 is Green and Red.
0018,  3423,2,2            retlw   0x23            ; state==1 is Amber and Red/Amber
0019,  3414,3,3            retlw   0x14            ; state==3 is Red   and Green
001A,  3432,4,4            retlw   0x32            ; state==4 is Red/Amber and Amber.
,,,5
,,,6            ; Function using two loops to achieve a delay.
001B,  3005,7,7 wait       movlw   5
001C,  0091,8,8            movwf   l1
,,,9
001D,  2021,0,0 w1         call    wait2
001E,  0B91,1,1            decfsz  l1
001F,  281D,2,2            goto    w1
,,,3
0020,  0008,4,4            return
,,,5
,,,6
0021,  0192,7,7 wait2      clrf    l2
0022,  0B92,8,8 w2         decfsz  l2
0023,  2822,9,9            goto    w2
0024,  0008,0,0            return
,,,1            END