program to display student number

[trevordunstan]

Hey there guys, how is everyone,

I am doing a computer engineering module at uni and have an assignement to produce a program on thrsim11 software to display my student number 1 digit at a time on a seven segment display. I have written a basic test program to do this but I am having trouble getting the numbers to display correctly. I know the hexpat data is correct as I have tested it but when i run the program all the segments on the LED light up and then turn off after the loop has finished. Would someone look over my code and tell me if I am going about this the right way or am I totally off course. Any advice or help would be greatly appreciated

Cheers guys !! sorry for the bad formatting

prb equ $1004 Peripheral port B
ddrb equ $1006 Data direction register B
prc equ $1003 Peripheral port C
ddrc equ $1007 Data direction register C
delay equ $bd4 value for 1 second time delay
program equ $00a0 start address of program
reset equ $fffe reset vector
eod equ $23 end of data


org $0000
hexpat fcb $3f,$03 hexpat 0-9
fcb $5b,$4f
fcb $66,$6d
fcb $7d,$07
fcb $7f,$6f
studnumber fcc '0085755#'


org program
start
ldaa #$ff all port B line output
staa ddrb set port B lines
ldaa #$01 pc0 line output
staa ddrc set port C lines

ldy #studnumber point index register Y to first student number digit
next ldab 00,y load first digit into Accum B
cmpb #eod compare EOD marker
beq stop if EOD stop program
andb $0f convert to binary
ldx #hexpat point indx reg X to hexpat
abx add offset ie add accum B to index reg X
ldaa 00,x get hexpat into accum a

staa prb output display word
ldaa #$00 get enable word
staa prc enable the display
ldab #$01 counter for loop 2
loop2 ldx #delay counter for 1 second delay
loop1 dex decrement counter 1
bne loop1
decb decrement counter 2
bne loop2 display (1 X 10 sec)
ldaa #$01 get disable word
staa prc disable display
iny increment index Y to point to next digit
bra next repeat process until EOD
stop jmp stop end of program

org reset
fdb start set reset vector to start