VGA 1280x1024 tile driver question

Electrodude

Hi

In vga_1280x1024_tile_driver_with_cursor.spin, line 451 reads:

djnz    cnt,#build_2y           'another two scan lines?

Line 457 reads:

cmp     cnt,phsb        wz      'sync enabled? (cnt=0)

I understand how special registers are used as variables in this program, but isn't cnt read-only and auto-updated? I don't understand this.

Thanks,
Electrodude

potatohead

http://forums.parallax.com/showthread.php?89497-Using-the-shadow-registers-behind-PAR-CNT-INA-INB

Rayman

that is funny isn't it... Maybe cnt is only updated when it's the source and not destination?


Probably something you only want to do if your name is Chip Gracey though...

Electrodude

Thanks. I thought stuff written there would just get thrown away.