MCU instruction set identification

[nikonhackerastronomer]

Hi,

First post here from Nikon Hackers. We run into a problem trying to identify the instruction set for a certain type of MCU in order to disassemble.

The package looks like this:


We pretty much rule out the instruction set we encountered (ARM, MIPS, FR80, H8/H8SX, etc) by running binwalk and searching for their typical opcode (RTN, CALL, LDI).
The marking indicates it's one from Japanese.

Is there anyone here familiar with the package marking? Or the ROM image, download here.

Thanks!

[chicken]

From the font and guessing (based on your nick name) it's out of a Nikon camera, I'd say NEC/Renesas. Maybe V850?

[chicken]

On a second thought, it's probably just a system controller, i.e. managing buttons and power-up/down. So I'd go with the lower power MCUs like their RL78 family or its NEC predecessor 78K
https://www.renesas.com/en-us/products/microcontrollers-microprocessors/rl78.html

[amyk]

Renesas

http://mms.businesswire.com/bwapps/mediaserver/ViewMedia?mgid=145612&vid=5&download=1 (from http://www.businesswire.com/news/home/20080804005277/en/Renesas-Technologys-H8SX-Family-Devices-Offer-EXDMA )