[flashrom] Nec/Renesas 78k0s flash programming?

[Stefan Tauner]

On Mon, 30 Mar 2015 15:56:06 +0000
Riccardo Delpopolo Carciopolo <rdelpopolo at gmail.com> wrote:

> Hi,
> I've used flashrom with pickit2 in past.
> I'm a newbie but I'd like to add support for this MCUs by myself.
> On Internet exist some parallel programmer but I want to program a 78k0s
> flash my with the uart protocol.
> We're can I start from?
> It requires some vpp pulses to enable the uart programming mode.

I don't think that flashrom is the right tool for the job of writing
the flash memory of a microcontroller. Usually there are dedicated tools
for this... but I guess the 78k0s are not really popular? You can of
course use flashrom or at least its serial.c as a base for your tool.

The protocol seems to be documented in a public application note:
http://documentation.renesas.com/doc/DocumentServer/U17739EJ3V0AN00.pdf

I am not sure about pulses thing. AFAICT the flash mode is enabled if
FLMD0 is high when reset is released. I am however unsure if the
following pulses on the same pin (FLMD0) are to be output by the
programmer or are a way for the chip to indicate how it needs to be
accessed... the language in the AN is abysmal. I would apply VCC to
FLMD0 on reset release with a pull-up resistor and measure if the chip
outputs anything on the port...

Anyway this is rather off-topic... good luck with your project!
-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner