Need Help Identifying This IC

[Guitarfreak302]

I am trying to ID this IC so I can repair this circuit board. The IC is intact in the picture but it now has some leads missing. The circuit is from a Clarion marine radio external remote. The remote is wired not wireless. The remote model is CMRC3D. It is now removed from the board and is supposed to go where it is labeled U2. I included a very crude schematic of what I traced out so far. Looks like GND is on pin 1 and power is pin 20. Your help would be appreciated. Thank you.

Ryan

[ondraN]

It looks like some MCU. It probably won't replace it because you don't know its internal microcode.

[Guitarfreak302]

Thanks for the reply. I thought it looked like a MCU too but was curious which one it could be.

[moffy]

Thanks for the reply. I thought it looked like a MCU too but was curious which one it could be.

I thought maybe a bit more like a serial keyboard encoder, similar to: https://ece-classes.usc.edu/ee459/library/datasheets/ede1144.pdf
The keys look like they are scanned in a matrix and the data is sent serially out Remocon on CN2. It might help to see what the chip is that receives the data, if it is a dedicated receiver chip.

[Guitarfreak302]

The chip that receives the data is a M30622MEP which is a 16 bit MCU. Remocon connects to pin 4 which is labeled as P9_1/TB1IN/SIN3.

[moffy]

The chip that receives the data is a M30622MEP which is a 16 bit MCU. Remocon connects to pin 4 which is labeled as P9_1/TB1IN/SIN3.

SIN3 might mean 'Serial In 3', which would be a UART, so it looks like the encoder might be sending the key data via a logic level RS-232 serial data stream.
According to the brief data sheet it looks like the M30622 has 3 UARTs: https://www.renesas.com/us/en/document/dst/m16c62p-group-m16c62p-m16c62pt-datasheet

[Guitarfreak302]

That actually makes sense now. Thanks