Re: [avrdude-dev] Verification errors with TPI and PDI programming

[Joerg Wunsch]

As Joakim Lubeck wrote:

> When I use usbasp (latest firmware) with TPI (tested tiny10, 20, 40)
> it gives me verification errors, like

...

> But it works without problems if I use the version RELEASE_5_11_1.

This is kind of strange.

I just compared the USBasp code in AVRDUDE between RELEASE_5_11_1 and
trunk.

Most of the differences relate to a modified USB search algorithm, so
that's completely unrelated.

Two further changes are in the (non-TPI) paged load and paged write
routines, adding the current (page) address to the buffer pointer in
order to obtain the data.  These changes became necessary since the
paged load and write routines are now called from the upper layer once
per page, while they have been called once per memory region in the
past (so the bug always existed, but did not have any effect prior).

No changes have been applied at all to the TPI-related code.

So it's really not quite clear to me why the TPI programming behaviour
would have changed between both versions.

Perhaps I'll add some debugging code to usbasp.c in order to have the
-vvvv option provide a communication trace.  Maybe we can find a
difference between both versions that way.
-- 
cheers, Joerg               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/
Never trust an operating system you don't have sources for. ;-)