led1s.sdi

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。任何试图破坏Microchip 代码保护功能的行为均可视 为违反了《数字器件千年版权法案（Digital Mille

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,,,;
,,,;       Source File:    LED1S.ASM
,,,;       Author:         MPB
,,,;       Date:           2-12-05
,,,;
,,,;       Output binary count is stepped manually
,,,;       and reset with push buttons.
,,,;       Demonstrates software delay switch debounce
,,,;
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,,,        PROCESSOR 16F877        ; Define MCU type
00002007,3733,,        __CONFIG 0x3733         ; Set config fuses
,,,
,,,; Register Label Equates....................................
,,,
,,,PORTB   EQU     06      ; Port B Data Register
,,,PORTD   EQU     08      ; Port D Data Register
,,,TRISD   EQU     88      ; Port B Direction Register
,,,Timer   EQU     20      ; GPR used as delay counter
,,,
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,,,
,,,; Initialise Port B (Port A defaults to inputs).............
,,,
00000000,1683 1303,,        BANKSEL TRISD           ; Select bank 1
00000002,3000,,        MOVLW   b'00000000'     ; Port B Direction Code
00000003,0088,,        MOVWF   TRISD           ; Load the DDR code into F86
00000004,1283 1303,,        BANKSEL PORTD           ; Select bank 0
00000006,280B,,        GOTO    reset           ; Jump to main loop
,,,
,,,; 'delay' subroutine ........................................
,,,
00000007,00A0,delay,delay   MOVWF   Timer           ; Copy W to timer register
00000008,0BA0,down,down    DECFSZ  Timer           ; Decrement timer register
00000009,2808,,        GOTO    down            ; and repeat until zero
0000000A,0008,,        RETURN                  ; Jump back to main program
,,,
,,,; Start main loop ...........................................
,,,
0000000B,0188,reset,reset   CLRF    PORTD           ; Clear LEDs
,,,
0000000C,1C86,start,start   BTFSS   PORTB,1         ; Test reset button
0000000D,280B,,        GOTO    reset           ; and clear LEDs
0000000E,1906,,        BTFSC   PORTB,2         ; Test step button
0000000F,280C,,        GOTO    start           ; and repeat if not pressed
,,,
00000010,30FF,,        MOVLW   0FF             ; Delay count literal
00000011,2007,,        CALL    delay           ; Wait for count
00000012,1D06,,        BTFSS   PORTB,2         ; Test step button
00000013,280C,,        GOTO    start           ; and wait if not released
00000014,0A88,,        INCF    PORTD           ; Increment LEDs
00000015,280C,,        GOTO    start           ; Repeat always
,,,
,,,        END                     ; Terminate source code