LAB5.ASM

;==============================================================================
;
; Lab 5
; SEG7.asm
;
; Displays a message onto 7-segment LED displays.
;
;==============================================================================

; Assign components of the training board into the
; assembly program.

INDF    EQU         0X00
STATUS  EQU         0X03            ; Status register
FSR     EQU         0X04
PORTA   EQU         0X05
PORTB   EQU         0X06
PORTC   EQU         0X07
PORTD   EQU         0X08
PORTE   EQU         0X09
TRISA   EQU         0X85
TRISB   EQU         0X86
TRISC   EQU         0X87
TRISD   EQU         0X88

;======================= STATUS Bits ==========================================
; Components of the status register to be used.
; Intended for bank selection.

C       EQU         0X0             ; Carry Flag
DC      EQU         0X1             ; Digit Carry Flag
Z       EQU         0X2             ; Zero Flag
PD      EQU         0X3             ; Power Down Bit
TO      EQU         0X4             ; Watch Dog Time out Bit
RP0     EQU         0X5             ; Bank Select
RP1     EQU         0X6             ; Bank Select, Unused
IRP     EQU         0X7             ; Unused

;======================= BANNER ===============================================
BANNER  EQU         0X70
BAN_I   EQU         0x20               ; 0-(BAN_SZ-1)
CNT_LP1 EQU         0X21
;======================== TIMER ================================================
TMP1    EQU         0X7F
TMP2    EQU         0X7E
TMP3    EQU         0X7D
;==============================================================================
       __CONFIG 0X3FF2              ;

        ORG         0X00            ; RESET VECTOR
        GOTO        START
        ORG         0X04            ; INTERRUPT VECTOR
        RETFIE
START
                                    ; Creating banner
                                    ; Assign banner to
                                    ; general registers

        MOVLW       0X11            ; 'A'
        MOVWF       BANNER
        MOVLW       0X00            ; 'B'
        MOVWF       BANNER+1
        MOVLW       0X63            ; 'C'
        MOVWF       BANNER+2
        MOVLW       0X85            ; 'D'
        MOVWF       BANNER+3
        MOVLW       0X61            ; 'E'
        MOVWF       BANNER+4
        MOVLW       0X71            ; 'F'
        MOVWF       BANNER+5
        MOVLW       0X09            ; 'G'
        MOVWF       BANNER+6
        MOVLW       0X91            ; 'H'
        MOVWF       BANNER+7
        MOVLW       0X11            ; 'A'
        MOVWF       BANNER+8
        MOVLW       0X00            ; 'B'
        MOVWF       BANNER+9
        MOVLW       0X63            ; 'C'
        MOVWF       BANNER+D'10'
        MOVLW       0X85            ; 'D'
        MOVWF       BANNER+D'11'

                                    ; configuring PORTA & PORTB
        BSF         STATUS,RP0      ;
        BCF         STATUS,RP1      ; Select Bank 1
        CLRF        TRISA           ; PORTA is config'd to output only
        CLRF        TRISB           ; PORTB is config'd to output only
        CLRF        TRISC           ; ~NEW!~ PORTC is config'd now
        CLRF        TRISD           ; ~NEW!~ PORTD is config'd too
        BCF         STATUS,RP0      ; Select Bank 0
        MOVLW       0XFF
        MOVWF       PORTB           ; all off
        MOVWF       PORTA           ; turn off DIS4-1
        MOVWF       PORTC           ; yes
        MOVWF       PORTD           ; likewise
        ;INCF        PORTA          ; for testing

                                    ; Display banner on the 7-seg
LOOP1
        MOVLW       8
        MOVWF       CNT_LP1         ; Assign loop counter
        CLRF        BAN_I

LOOP2
        MOVLW       BANNER
        ADDWF       BAN_I,W
        MOVWF       FSR
        MOVF        INDF,W
        MOVWF       PORTB           ; send a character to 7-SEG
        MOVLW       0XFE            ;
        MOVWF       PORTA           ; turn on #1 7-SEG (DIS1)
        ;CALL        DLY_1S
        INCF        FSR
        MOVF        INDF,W
        MOVWF       PORTB           ; send a character to 7-SEG
        MOVLW       0XFD            ;
        MOVWF       PORTA           ; turn on #2 7-SEG (DIS2)
        ;CALL        DLY_1S
        INCF        FSR
        MOVF        INDF,W
        MOVWF       PORTB           ; send a character to 7-SEG
        MOVLW       0XFB            ;
        MOVWF       PORTA           ; turn on #3 7-SEG (DIS3)
        ;CALL        DLY_1S
        INCF        FSR
        MOVF        INDF,W
        MOVWF       PORTC           ; send a character to 7-SEG
        MOVLW       0XF7            ;
        MOVWF       PORTD           ; turn on #4 7-SEG (DIS4)
        ;CALL        DLY_1S
        INCF        BAN_I
        DECFSZ      CNT_LP1
        GOTO        LOOP2
        GOTO        LOOP1           ; loop forever

        GOTO $

DLY_1S
        MOVLW       26              ; (1)X
        MOVWF       TMP1            ; (1)
LP1     MOVLW       250             ; (1)Y
        MOVWF       TMP2            ; (1)
LP2     MOVLW       255             ; (1)Z
        MOVWF       TMP3            ;
LP3     DECFSZ      TMP3,F          ; (1)(2)
        GOTO        LP3             ; (2)
        DECFSZ      TMP2,F          ; (1)(2)
        GOTO        LP2             ; (2)
        DECFSZ      TMP1,F          ; (1)(2)
        GOTO        LP1             ; (2)
        RETURN

        END