Tom Sylla wrote:
I'm just a bit curious - are there settings/registers in northbridges which can seriously brick a mainboard and/or RAM (physically) if abused properly?
There is nothing you can do from software to physically harm SDR, DDR, or DDR2 devices.
100% agree with Tom. I suppose if you somehow tickle some crazy bug to make the controller output the wrong voltage you could do something bad to the rams but the chances of that are so low they aren't even worth considering. Remember thats a really mature chipset.
I've put all manner of wrong settings in those chips and during the development of the Bitworks/IMS board we did all sorts of "Bad" things to the ram and it kept on plugging.
So I think you are safe.
Thinking about this brings back a few memories.
1) I found in my testing that you can do things to the north bridge that will crash it in such a way that a reset does not fully fix. It's very sneaky, things just start behaving really weird and your code just seems to start failing for no good reason. But not so bad as to suspect that its hardware. Especially if you are doinking with the register settings at the time.
The only fix is to _remove_ power from the board. And on the ASUS I seem to remember having to remove the CMOS battery as well. (Bitworks/IMS had no battery) So I recommend you remove the battery and power cycle frequently.
2) The 66Mhz/100Mhz operation of the front side bus is controlled via a jumper. The Bitworks board however was never qualified to run at 100Mhz. So all the settings are for 66Mhz. If you run with the 66Mhz drive settings yet have the jumper set to 100Mhz you are in for a lot of frustration. Just depends on the quality of your ram and the board layout. I recommend that you do all you development with 66Mhz and then work out the 100Mhz settings after you have the code working. I can't help much with the 100Mhz settings. You will need to dump a Factory BIOS set to 100Mhz and compare how they setup the drive settings.