#2341 - xponder - Sun Feb 02, 2003 5:57 am
Hi! all GBA expert,
I am not a game devloper but I am using GBA for ARM programming practice and intend to use GBA console as control engine for toy.
I am very doubt, where is EWRAM phisically locate (in the GBA unit or in the game cartridge)?
- xponder
#2344 - tepples - Sun Feb 02, 2003 7:04 am
EWRAM is located in the GBA. It is called "external" because it is external to the ARM core.
When I opened my GBA to install an Afterburner kit (which I removed after it made TOD and everything else look extremely washed out), I saw two packages that dominated the mainboard. One is marked AGB CPU; I assume it contains the ARM7TDMI and GBZ80 cores. I didn't look too closely at the other chip, but I assume that that's the EWRAM.
But some Game Paks do contain a small amount (up to 64 KB) of static RAM to maintain the game's settings, high scores, player progress, etc. This is mapped at 0x0E000000-0x0E00FFFF. It's quite slow to read or write (8 wait states IIRC), and because this RAM uses the old GB bus protocol, all access is 8-bit.
_________________
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#2346 - xponder - Sun Feb 02, 2003 8:31 am
Thankyou for your answers splam, tepples.