Slot-2 Crash Course?

[jpopadic]

Hi everybody. Long time reader, first time poster.

Is there any documentation out there on how to talk to the bus on Slot-2? I'm interested in constructing some peripheral hardware using this interface. Is it simply a matter of writing to the correct memory address?

Any nudges in the right direction would be appreciated.

Cheers!
J

[WinterMute]

Kind of depends on what it is you want to do really, the simplest interface on there is probably the SRAM bus since it doesn't need latches for addressing.

Couple of links that might help

http://www.brolinembedded.se/projects/flashcart/

http://www.ziegler.desaign.de/GBA/gba.htm

[jpopadic]

Thanks for the reply and the links. Specifically, I'm trying to interface Slot-2 with some homemade external hardware. I'm not fussed about the address lines. I'd be happy if I could just read and write to the 8 data lines.

The SRAM approach worked a trick! For example, to read the data lines the following works:

sysSetBusOwners(true, true);
u8 gba_bus_state = 0;
memcpy (&gba_bus_state, (void*)0x0A000000, 1);

Haven't got any output hardware with me at work (just using the Guitar Hero controller to toggle the lines) but imagine output should be pretty similar.

Thanks!

[Key_46]

Hello, i see that you have solved the hardware communication system, i'm having the same problem, currently i'm trying to measure the output using a voltimeter pinned to VDD and one of the eight data pins and trying to write 0xFF and 0X00 to see any change but the pins are aways at 3.2 volts, no logical zero, how did you connect yor hardware?

Thanks.