Changes

DSi DWM-W015

There appear to be 3 WiFi modules at use in the DSi.

The DSi WiFi module actually contains two wireless chips, a Mitsumi MM3218 for DS compatibility and a more modern Atheros AR6002G, which share the antenna through an RF switch.  The DS WiFi is configured through profiles 1-3 and is limited to 802.11b 1-2Mbps and WEP encryption while the Atheros supports 802.11g rates and WPA encryption, configured through profiles 4-6.

The original DSi DWM-W015 module features two wireless chips; a Mitsumi MM3218 for DS compatibility and a more modern Atheros AR6002G BGA which share the antenna through an RF switch.  The DS WiFi is configured through profiles 1-3 and is limited to 802.11b 1-2Mbps and WEP encryption while the Atheros supports 802.11g rates and WPA encryption, configured through profiles 4-6.

The Mitsumi WiFi is controlled through data in the NVRAM (eg: Region code) http://www.daftcode.net/gbatek/ds#dsfirmwarewificalibrationdata while the Atheros appears to have it's configuration stored elsewhere.

http://www.flickr.com/photos/micahdowty/3846960965/sizes/o/in/photostream/

 

Note the circle in this image shows a 10k resistor from pin 5 WP to GND, which the ST M45PE10 datasheet indicates will write-protect the first 64K. To disable this protection according to the SPI datasheet, remove the resistor and solder pin 5 to pin 6 VCC.

If this module is disconnected the DSi turns on to a black screen, presumably because it can't read the NVRAM.  If the DSi doesn't like the data contained on the module it will give either error 0000FEFE or 0000FE00 at poweron.

The DSi only uses a tiny portion of the 128KB available for startup data, calibration, and user settings.  Modules with SPI flash can be written to in DS mode, which enables the installation of WiFi loader "dslink" which can then be launched in DSi mode via save-game hacks in DSi hybrid games.  Newer modules with the 5A32 chip are incompatible with this, most likely because the custom chip has significantly less storage.  khmann had success backing up the data in a 5A32 using an SPI connection to a DS cartridge, removing the 5A32 and installing a pre-programmed ST M45PE20 2Mbit SPI flash chip which enabled use of the this exploit on a newer console.

 

Nintendo's reasons for changing the NVRAM chip are unclear, but it seems all DWM-W015 have connections for both types of chips and the change to the limited chip occurred prior to the release of the dslink exploit.

 

The Mitsumi WiFi is controlled through data in the NVRAM (eg: calibration data, allowed channels) http://www.daftcode.net/gbatek/ds#dsfirmwarewificalibrationdata while the Atheros configuration is likely stored in the other tiny IC on the board, an i2c eeprom.

There are at least two hardware versions of the module, the original using a 1Mbit SPI flash ST M45PE10 [[Media:STM45PE10.pdf]] and a newer version which I had using a very tiny chip labeled "5A32" and I think "8936" but it might be "B936".  Note the circle in this image shows a 10k resistor from pin 5 WP to GND, which the ST M45PE10 datasheet indicates will write-protect the first 64K.  If you would like to disable this protection, remove the resistor and solder pin 5 to pin 6 VCC.

The DSiXL or DSi/LL module is labeled DWM-W024, and includes only an Atheros AR6013G-AL1C, a 5A32 variant, empty SPI flash pads, and another small chip likely to be the Atheros-native i2c configuration.

khmann had success backing up the 5A32 using the above pictured connection to a DS cartridge, removing the 5A32 and installing a ST M45PE20 2Mbit SPI flash salvaged from said NDS game with said data.  not sure what this "gets you" yet... but theorized that this change might have something to do with newer DSi units unable to use the CookingCoach dslink exploit

If this module is disconnected the DSi turns on to a black screen, because it can't read the NVRAM.  If the DSi doesn't like the data contained on the module it will give either error 0000FEFE or 0000FE00 at poweron.