Important news! After someone on #Cakey ripped off an MCU from a board, we discovered that there was printing on the bottom of the MCU.... just 3 characters, but it has led to some interesting results.... so, previous speculation said that the MCU was 8 bit, this does not seem to be the case. Rather, it seems to have a 16 bit processor with lots of 8 bit peripherals and a configuration option to have either 8 16-bit registers or 16 8-bit registers, anyone who'd like to check up on this can look here:
http://documentation.renesas.com/doc/products/mpumcu/e602095_h83217.pdf
I strongly think this is our culprit, simply repackaged specially for nintendo... most of the chips here are 64 pin/pad and they offer a 16kB EEPROM option, which all matches the 3ds... the block diagram says it supports i2c, which the 3ds supports.... everything looks like it simply matches the 3ds more so than the other MCUs