gbadev.org forum archive

This is a read-only mirror of the content originally found on forum.gbadev.org (now offline), salvaged from Wayback machine copies. A new forum can be found here.

Hardware > FLASH vs SRAM

#4955 - Vortex - Tue Apr 15, 2003 7:34 pm

Hello,

Is it possible to use battery-backed SRAM instead of Flash memory in a homebrew "flash" cart? The SRAM should be used to store the game binary files (ROM Images), not for saving games.

I know the SRAM is more expensive than Flash, but I hope using SRAM I can program the cart for 1-2 seconds instead of minutes. For me, as a developer, fast access times are much more important than memory size.

Thanks

#4957 - tepples - Tue Apr 15, 2003 7:41 pm

Vortex wrote:
Is it possible to use battery-backed SRAM instead of Flash memory in a homebrew "flash" cart?

If your board design allows for mapping SRAM to 0x08000000, yes.

Quote:
I know the SRAM is more expensive than Flash

At the GBA's speed, you may be able to get away with a design that uses cheap DRAM instead.
_________________
-- Where is he?
-- Who?
-- You know, the human.
-- I think he moved to Tilwick.

#4961 - ampz - Tue Apr 15, 2003 9:58 pm

Actually, I've thought about this for quite some time.
Not just a simple SRAM based cart, but a 3:rd party devkit. With support for a real debugger. Breakpoints, singlestepping, and so on...
Download times of 1-2sec is quite possible.

Yes, DRAM could be used, however, DRAM requires a DRAM controller. Complicates things a bit.
DRAM also requires alot more power. Not good for battery backup applications. Of course, for development purposes battery backup makes very little sense anyway.

SRAM is cheap enough to build a 32Mbit SRAM cart for a reasonable price. (depending somewhat on the the definition of "reasonable")