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DS development > Interfacing with Slot-2 SRAM

#175362 - Key_46 - Sun Oct 31, 2010 7:13 pm

I've seen many expamples of how to interface custom hardware with nds using Slot-2 ROM, but none using the SRAM mode.

looking on youtube i found a video where someone in fat did this, the SRAM Address pins are connected directly to LED which in my opinion is quite easier to work with than multiplexing stuff.

A few said they could read from the data lines, which is easy as call

Code:
val = SRAM[0];


i've managed to get this part working but i'm still confused about how to control the output on the address lines.

I thought this would be automatic when i call SRAM[i], but all lines are aways at 3.25V. My assembly is identical to this video:

http://www.youtube.com/watch?v=Sf9B8NemvAk

what makes me believe that's software related... somehow...

here's what i've been using as code:

Code:


REG_EXMEMCNT = (1<<14) | (0<<6) | (1<<5) |
   (0<<4) | (1<<3 ) | (1<<2) | (1<<1) | (1<<0);

irqSet(IRQ_VBLANK, VBlank);
consoleDemoInit();

while(1)
{
   data = SRAM[1]; //AD0 High, all the rest Low
   swiWaitForVBlank();
}



The reading is perfect but the SRAM Address lines does not change...[/quote]