I tested ao68000 in verilog simulator. I tried 68000 monotr program,but dose not work.
I think DBRA(DBcc) have a problem.
68k montor source :
lea traperr(pc),a0
lea $80,a1
moveq #15,d0
trapset move.l a0,(a1)+ dbra d0,trapset
simulation d0 value : $0000000f $0000000e . . $00000000 $0000ffff <- dbra loop not end !! $0000fffe <- ????
Thank you
Thank you for your bug report.
You are correct - there was a bug in the DBcc opcode microcode. I have commited a fix to the microcode.
If you are willing to check the fix, please do - and send a reply comment :)
Once more, thank you. Aleksander Osman.
Thank you for update! 'DBRA' code is ok. I continue simulation it.