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- ;
- ; Ex3.asm ---- Example program 3 for DRAGON12 board, Rev. E (c)2004, EVBplus.com
- ; Written by Wayne Chu
- ;
- ; Function: Displays the word 'HELP' on the 7-segment LED display,
- ; the 7-segment is multiplexed at 1ms per digit fresh rate,
- ; 250Hz fresh rate for 4 digits.
- ;
- #include reg9s12.h ; include register equates
- ;
- ;
- DB6 equ $40
- DIG0: equ 8 ; PP3
- DIG1: equ 4 ; PP2
- DIG2: equ 2 ; PP1
- DIG3: equ 1 ; PP0
- TB1MS: equ 24000 ; 1ms time base of 24,000 instruction cycles
- ; 24,000 x 1/24MHz = 1ms at 24 MHz bus speed
- REGBLK: equ $0000
- STACK: equ $2000
- ;
- org $1000
- ;
- select: rmb 1
- d1ms_flag: rmb 1
- disp_data: rmb 4
- disptn: rmb 4
- org $1020
- offset: dw #0
- store: dw #0
- ;
- ; Segment conversion table:
- ;
- ; Binary number: 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
- ; Converted to 7-segment char: 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
- ;
- ; Binary number: $10,$11,$12,$13,$14,$15,$16,$17
- ; Converted to 7-segment char: G H h J L n o o
- ;
- ; Binary number: $18,$19,$1A,$1B,$1C,$1D,$1E,$1F,$20
- ; Converted to 7-segment char: P r t U u y _ -- Blank
- ;
- org $2000
- ;
- jmp start
- segm_ptrn: ; segment pattern
- fcb $3f,$06,$5b,$4f,$66,$6d,$7d,$07 ; 0-7
- ; 0, 1, 2, 3, 4, 5, 6, 7
- fcb $7f,$6f,$77,$7c,$39,$5e,$79,$71 ; 8-$0f
- ; 8, 9, A, b, C, d, E, F
- fcb $3d,$76,$74,$1e,$38,$54,$63,$5c ; 10-17
- ; G, H, h, J L n o o
- fcb $73,$50,$78,$3e,$1c,$6e,$08,$40 ; 18-1f
- ; P, r, t, U, u Y - -
- fcb $00,$01,$48,$41,$09,$49 ; 20-23
- ; blk, -, =, =, =, =
- ;
- seven_segment:
- pshx
- pshb
- ldx #segm_ptrn
- psha
- anda #$3f
- tab
- abx
- ldaa 0,x ; get segment
- pulb
- andb #$80 ; add DP
- aba
- pulb
- pulx
- rts
- start:
- lds #STACK
- ldx #REGBLK
- ldaa #$ff ; turn off 7-segment display
- staa ptp,x ; portp = 11111111
- staa ptj,x ; make PJ1 high to disable LEDs
- staa ddrb,x ; portb = output
- staa ddrp,x ; portp = output
- staa ddrj,x ; make port J an output port
- ldaa #$80
- staa tscr,x ; enable timer
- ldaa #DB6
- staa tios,x ; select t6 as an output compare
- staa tmsk1,x
- cli
- ldaa #$00
- staa ddrh,x ;porth = input
- ;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Do math in this section
- ldx #store ; load x with the address of "store"
- ldy #9 ; load index register with the number 4
- ;we use this as our counter for our loop
- ldaa 0,x ;load accumlator A with the contents of
- ;the memory location at x
- ldab #1 ;ldab with the number 1
- loop
- aba
- inx
- inx
- staa 0,x
- ldab -2,x
- dbne y loop ; decrement y on bit not equal
- end
- ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;End math
- begin:
- ;;;;;
- ;Algorithim for moving data into the right memory locations go here
- ldx store
- ldab offset
- abx
- ldaa 0,x
- asla
- asla
- asla
- asla
- staa disp_data
- ldaa 1,x
- anda $0F
- staa disp_data+1
- ldaa 0,x
- asla
- asla
- asla
- asla
- staa disp_data+2
- ldaa 1,x
- anda $0F
- staa disp_data+3
- ;disptn drives digit 1
- ;disptn+1 drives digit 2
- ;disptn+2 drives digit 3
- ;dispth+3 drives digit 4
- ;Once your bytes are in these locations
- ;the program jumps to the right subroutines and displays the data.
- ;you will probably have to manipulate the bits in the registers before
- ;storing them to these locations.
- ldx #disp_data
- jsr move
- jsr sel_digit
- ;
- wait: tst d1ms_flag
- beq wait
- clr d1ms_flag
- ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
- ;Button pressing and checking stuff goes here;
- ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
- jmp begin
- ;
- ; this routine moves 4 bytes of data into disptn (display pattern)
- ; and converts the pattern to 7-segment code.
- ; @ enter, x points the source address
- ;
- move: ldy #disptn
- mnext: ldaa 0,x
- jsr seven_segment ; convert Accu A to segment pattern, bit 7= DP
- staa 0,y
- inx
- iny
- cpy #disptn+4
- bne mnext
- rts
- ;
- ; multiplexing display one digit at a time
- ;
- sel_digit:
- ldx #REGBLK
- inc select
- ldab select
- andb #3
- tstb
- beq digit3
- decb
- beq digit2
- decb
- beq digit1
- ;
- digit0:
- ldaa disptn+3
- staa portb,x
- bclr ptp,x,DIG0 ; turn on digit 0
- bset ptp,x,DIG1 ; turn off all other digits
- bset ptp,x,DIG2
- bset ptp,x,DIG3
- rts
- digit1:
- ldaa disptn+2
- staa portb,x
- bset ptp,x,DIG0
- bclr ptp,x,DIG1 ; turn on digit 1
- bset ptp,x,DIG2 ; turn off all other digits
- bset ptp,x,DIG3
- rts
- digit2:
- ldaa disptn+1
- staa portb,x
- bset ptp,x,DIG0
- bset ptp,x,DIG1
- bclr ptp,x,DIG2 ; turn on digit 2
- bset ptp,x,DIG3 ; turn off all other digits
- rts
- digit3:
- ldaa disptn
- staa portb,x
- bset ptp,x,DIG0
- bset ptp,x,DIG1
- bset ptp,x,DIG2
- bclr ptp,x,DIG3 ; turn on digit 3
- rts
- timer6:
- ldx #REGBLK
- ; in an interrupt servicing routine the x register will be saved automatically
- ; the rti instruction will pop the x register off stack.
- inc d1ms_flag
- ldd #TB1MS ; reload the count for 1 ms time base
- addd tc6,x
- std tc6,x
- ldaa #DB6
- staa tflg1,x ; clear flag
- rti
- org $3E62
- fdb timer6
- end
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