assembly - MC68k assembler address syntax -

assembly - MC68k assembler address syntax -

i'm trying write programme take 8-bit value , write d0. masked 4-bit value. number supposed access number in a0 , write d1.

this number sent output.

this how i'm going @ it:

in_port equ $fffff011 out_port equ $fffff019 mask equ $0f org $4000 start: move.b in_port,d0 andi.b #mask,d0 move.b (0,a0,d0),d1 * problem area move.b d1,out_port jmp start org $5000 segcodes: dc.b $77,$22,$5b,$6b dc.b $2e,$6d,$7d,$23 dc.b $7f,$2f,$dd

my problem seems syntax around comment. nil written d1 , nil sent output.

i had forgotten add together address next command:

movea.l #$5000,a0

this writes destination of address can accessed correctly, think. please right me if i'm wrong.

assembly 68000