#avr Logs

Feb 07 2019

06:15 AM [1]MrMobius is now known as MrMobius
06:22 AM [1]MrMobius is now known as MrMobius
09:09 AM rue_mohr: -
04:05 PM pareidolia: I've got an avr asm program that references a memory location that should be out of bound (0x500) on an Atmega16 with 1024 bytes SRAM. What happens? Does it simply wrap around?
04:14 PM cehteh: just dont do that
04:44 PM samantaz__ is now known as samantaz
04:58 PM pareidolia: cehteh: I didn't do it, and the code obviously works
04:59 PM pareidolia: I just want to know why
04:59 PM cehteh: coincidence/by chance .. read datasheet, i only have the atmega328pb datasheet open here, dont see its defined anywhere
05:00 PM cehteh: even if it wraps around, first part of the sram address spaces are registers, then io-registers and more, only then the real sram
05:00 PM cehteh: and some instructions may not handle long/overflowing addresses correctly
05:01 PM cehteh: pretty much undefined land, at least malpractice
05:21 PM pareidolia: 0x500 - 0x400 is still 0x100 so it seems high enough
05:23 PM cehteh: still not very well defined you may be lucky .. or unlucky that it works, should be fixed
05:24 PM cehteh: unlucky because such may cause hard to find bugs later
05:25 PM cehteh: on some platforms such wrap arounds are well defined and can be abused, for mariginal gains in only soem corner cases
05:29 PM pareidolia: I believe you. I want to understand it so I can get rid of it :) I'll probably make some experiments. Write to location x+0x400 and read from location x.
06:52 PM [1]MrMobius is now known as MrMobius
08:09 PM ephemer0l is now known as ephemer0l_
11:32 PM day_ is now known as day