D70F3180GJ V850E/GP2

Can you confirm the 70F3180 part number?  I do not see this listed in the PG-FP5 list of supported devices.

List of MCUs supported by PG-FP5

I agree with you... the GP2 series is poorly represented in PG5, but I have the PR5 file specifically for this processor and the programmer accepts this file without errors... so there is hope that there is a datasheet for this processor)

Can I ask how you came to obtain the PR5 parameter file for this particular device?  I do not find this in the list on the web page:

www.renesas.com/.../pg-fp5-discontinued-product

there is a topic in the archive about this processor

I cannot find any info about this device.  There were several custom V850 devices made, and documentation is restricted to the original customer.  My guess is this was a custom device.

very sad if this is true...

So, is it possible to replace the factory loader from Renesas with your own? why am I asking - I found a reset, flmd0, flmd1. 3 pins left. I went through these 3 pins in various combinations sck si so. the processor did not respond.. this suggests that the bootloader has been replaced) is this possible?

Pretty difficult to guess on this.  Ever device has built-in firmware for factory programming over a serial interface, but that can be disabled by the user.  Without device specifications it is impossible to know for sure which pins handle what functions.  I have noticed them many if not most devices do seem to share common pins, it might be possible to analyze other similar public V850 devices with similar packaging to guess which pins might work.

Several more attempts to search for a connection yielded results, but rather strange ones. For each byte of a connection request, the processor responds in parallel, I can’t attach screenshots, it would be clearer.. I wonder what kind of response mode this is?

Which package is this chip (e.g. QFP100 or QFP80)?  And which pins have you found VCC/GND/XTAL?  I would be looking at similar devices (e.g. V850/Fx2) for possible common pin assignment.

Which package is this chip (e.g. QFP100 or QFP80)?  And which pins have you found VCC/GND/XTAL?  I would be looking at similar devices (e.g. V850/Fx2) for possible common pin assignment.

qfp 144 pin. gnd, +5v, +2.5v, flmd0, reset, mosi, miso, sck. xtal not use.

Here are 144pin QFP pin assignments from a couple of early V850 devices that *might* have similar pinout.

V850/Fx3 (were pin-compatible with Fx2 as I recall), from V850ES/Fx3 User Manual: Hardware

V850E/SJ3-H, V850E/SK3-H User's Manual: Hardware

I'll look into it, thank you very much!!