Jun
27
Tama-Go Microcontroller
Found it! Found it! Found it! Or at least I hope I did
The Tama-Go microcontroller appears to be a Generalplus GPLB5X series LCD controller.
Thanks to binary for the tip! He found several Japanese language sources stating that Sunplus and Epson do buisiness with Bandai. Generalplus is a subsiduary of Sunplus. And yes, I did compare the pad layout of every single reasonable Epson and Sunplus MCU with the Tamagotchi die before moving onto the Generalplus ones :S.
But this does seem a way better fit than any other microcontroller I’ve looked at. A layover is below for dramatic effect
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I’m not exactly sure what member of the series it is (there are four possibilities), but I can probably figure out by measuring the pad positions (they are very slightly different for each version), and it’s probably not particularily relevant because they use the same instruction set.
The specifications are as follows:
- 8 bit RISC microprocessor
- 1536 bytes RAM
- 320 or 640 Kbytes mask ROM (depending on model), baked to perfection for each customer
- 512 bytes LCD RAM
- 4 color grayscale LCD controller
- SPI (probably used for the EEPROM)
- Audio DAC
See the datasheet for more details.
So this means that code is in ROM. I guess the next step is figuring out how to dump the ROM
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Wow! Great job Natalie. That totally looks like a match.
I was going to say that 1536B of ram seems like a really bizarre number, but it’s exactly 6 256B blocks (or 3 512B blocks)… so I guess it’s reasonable.
The sheet actually says “usable RAM”, so it might actually have a more even amount, but some is reserved or something.
In that case 2K with a 512B block reserved would seem to make sense, but that’s a guess on my part (although, probably a reasonable one).
A bootloader would probably fit in 512B.
What am I thinking? That’d be in ROM.
They might mirror it to RAM on boot for faster execution, but with that little memory available, it would seem pretty wasteful. Perhaps it’s an interrupt vector table?
(also, why can’t we edit comments?)
Okay final comment, I promise… ^^;
The mysterious missing 512B of RAM is probably the LCD RAM (which is conveniently 512B as the specs you posted mention).