Seven Segment Display

Seven Segment Display/152120201044.asm

@@ -0,0 +1,153 @@
+    LIST 	P=16F877A
+    INCLUDE	P16F877.INC
+    __CONFIG _CP_OFF &_WDT_OFF & _BODEN_ON & _PWRTE_ON & _XT_OSC & _WRT_ENABLE_OFF & _LVP_OFF & _DEBUG_OFF & _CPD_OFF
+    radix	dec
+
+    ; Reset vector
+    org 0x00
+    
+    BSF	    STATUS, RP0		; Select Bank1
+    CLRF    TRISA		; PortA --> Output
+    CLRF    TRISD		; PortD --> Output
+    BCF	    STATUS, RP0		; Select Bank0
+
+    
+    CLRF    PORTD		; PORTD = 0
+    CLRF    PORTA		; Deselect all SSDs	
+    
+    
+    digit0	    EQU	    0x20
+    digit1	    EQU	    0x21
+    no_iteration    EQU     0x22
+    i		    EQU     0x23
+    LUT		    EQU     0x24
+    
+    CALL    Init_LUT
+		    
+    MOVLW	0
+    MOVWF	digit0
+
+    MOVLW	0
+    MOVWF	digit1
+    
+    MOVLW	90		   
+    MOVWF	no_iteration		   
+
+    
+    
+for:    
+    MOVLW	1		    
+    MOVWF	i		   
+loop_begin:	
+    MOVF	i, W		    
+    SUBWF	no_iteration, W	   
+    BTFSS	STATUS, C	   
+    GOTO	loop_end	    
+loop_body:			    
+   
+    BSF		PORTA, 5
+    BCF		PORTA, 4 
+    MOVF	digit0, W
+    CALL	GetCode      ; SSDCodes [digit0]  
+    MOVWF	PORTD
+    CALL	Delay5ms
+    
+    BSF		PORTA, 4
+    BCF		PORTA, 5 
+    MOVF	digit1, W
+    CALL	GetCode      ; SSDCodes [digit1]  
+    MOVWF	PORTD
+    CALL	Delay5ms
+    
+    INCF	i, F		    ; i++
+    GOTO	loop_begin
+loop_end:
+    
+    CLRF	i
+    INCF	digit0, F
+    
+    ;     if (digit0 == 10)
+    MOVLW	10		   
+    SUBWF	digit0, W		   
+    BTFSS	STATUS, Z	   
+    GOTO	not_equal
+ 
+    MOVLW	0
+    MOVWF	digit0
+    INCF	digit1, F
+
+not_equal:
+    
+    ;      if (digit1 == 2 && digit0 == 1)
+    MOVLW	1		  
+    SUBWF	digit0, W		   
+    BTFSS	STATUS, Z	    
+    GOTO	loop_begin
+   
+    MOVLW	2		   
+    SUBWF	digit1, W		   
+    BTFSS	STATUS, Z
+    GOTO	loop_begin
+    
+    MOVLW	0
+    MOVWF	digit0
+    MOVLW	0
+    MOVWF	digit1
+    GOTO	loop_begin
+
+    
+GetCode:
+    MOVWF   FSR		; FSR = number
+    MOVLW   LUT		; WREG = &LUT
+    ADDWF   FSR, F	; FSR += &LUT
+    MOVF    INDF, W	; WREG = LUT[number]
+    RETURN
+    
+    
+Delay5ms:
+	k	EQU	    0x70		    ; Use memory slot 0x70
+	l	EQU	    0x71		    ; Use memory slot 0x71
+	
+	MOVLW	    d'5'		    ; 
+	MOVWF	    k			    ; i = 5
+Delay5ms_OuterLoop
+	MOVLW	    d'250'
+	MOVWF	    l			    ; j = 250
+Delay5ms_InnerLoop	
+	NOP
+	DECFSZ	    l, F		    ; --j == 0?
+	GOTO	    Delay5ms_InnerLoop
+
+	DECFSZ	    k, F		    ; --i == 0?
+	GOTO	    Delay5ms_OuterLoop
+	RETURN
+    
+    
+Init_LUT:
+    MOVLW   B'00111111'		; 0
+    MOVWF   LUT			; LUT[0] = WREG    
+    MOVLW   B'00000110'		; 1
+    MOVWF   LUT+1		; LUT[0] = WREG    
+    MOVLW   B'01011011'		; 2
+    MOVWF   LUT+2		; LUT[0] = WREG    
+    MOVLW   B'01001111'		; 3
+    MOVWF   LUT+3		; LUT[0] = WREG    
+    MOVLW   B'01100110'		; 4
+    MOVWF   LUT+4		; LUT[0] = WREG    
+    MOVLW   B'01101101'		; 5
+    MOVWF   LUT+5		; LUT[0] = WREG    
+    MOVLW   B'01111101'		; 6
+    MOVWF   LUT+6		; LUT[0] = WREG    
+    MOVLW   B'00000111'		; 7
+    MOVWF   LUT+7		; LUT[0] = WREG    
+    MOVLW   B'01111111'		; 8
+    MOVWF   LUT+8		; LUT[0] = WREG    
+    MOVLW   B'01101111'		; 9    
+    MOVWF   LUT+9		; LUT[0] = WREG  
+    RETURN
+    
+    
+    MOVWF   PORTD    	; Send the result stored in WREG to PORTD to display it on the LEDs
+    
+LOOP    GOTO    $	; Infinite loop
+    END