Anyone with specs for old Hitachi components?

[Buchholz, Steven]

Thanks for the reply Christian!

Unlike the apparent expectations of others, I realize this is a bit of a
fishing expedition, and truly appreciate the fact you took the time to reply
on my request.  The one thing that I do not want to do is post information
to the list that is felt to be inappropriate.  I am posting this reply with
the details that I am aware of ... if there are any who feel this discussion
should be taken off line, please don't hesitate to let me know!

So far I haven't gotten any info on the 46506 ... and yes, it wouldn't
surprise me to hear that the 46510 was a close cousin.  On the boxes I've
opened up I have yet to find any large chips with odd packages ... unless
that ASIC was in some sort of a PQFP package ... I have one of these mounted
on that ceramic substrate I mentioned in the earlier note. ... and no, I
don't recall ever seeing a label "JECS" anywhere on the box ... perhaps that
is a Nissan specific label ...

You have an interesting point about the different part available only on the
ECU with the knock sensing capability.  That is something I had not
considered ... perhaps the knock sensing is done on a completely different
processor like a microcontroller that serves as a peripheral to the main
microprocessor in the ECU.  I am looking at several different versions of a
similar control system (in a way they are subsequent generations of the
original) ... the first has no knock sensing, while the follow-on units have
an initial followed by a more refined version of knock control.  

It is interesting to hear that Hitachi used a uC with external RAM in your
app.  In the Audi boxes they seemed to go to the Hitachi proprietary HD6303
processors that have a small amount of internal RAM (which does have
provisions for external batery back up) and a built in multiplier.  

While just checking the old spec book I have for the 46510, I actually found
the best clue yet as to the origin of the chips we're looking for.  I found
a cross reference chart that gives the 46503, 46504 and 46505 as the "old
type numbers" for Hitachi's versions of the rotoMola stock 6800 peripheral
chips: 6843 FDC, 6844 DMAC and 6845 CRTC ... using that model, my chip would
be a 6846 (ROM, I/O, Timer) ... and yours would be a 6850 (ACIA) ???  I
don't have a Moto catalog here, but the cross ref I have says that the 46846
and 46850 fill those slots ... and at least in my ECU, the processor has
integral I/O, timer and serial interface functions.  If anyone happened to
find a HD46508, it is a 16-channel, 10-bit A=>D module ... perhaps it got
into an ECU somewhere ... 

I do have the databook that covers a lot of the old Hitachi parts (HD6803,
6303, 6809, 6309, HD68000, some peripheral parts) in Hitachi catalog #U70
... if anyone needs datasheets for any of these old processors, don't
hesitate to contact me and I'll do what I can to get the info to you ... 

Steve Buchholz
San Jose, CA (USA)
> 
> If you find anything on the 46506 I would be very very interested.
> My Nissan JECS ECU runs on a 6802 and sounds very similar
> to what you're looking at. Mine has a 42pin DIP except it's 46510
> which would have to be a damn close relation. Does your ECU
> have JECS mentioned on it anywhere?
> 
> Mine also has a big 64 pin ASIC with pins spaced less than 0.1"
> I take it yours doesn't.
> 
> I am sure from the disassembled code that one of these two chips
> has a hardware multiply in it used for table interpolation.
> 
> Don't assume that because you know that one chip is a (P)ROM
> that there won't be any others. My ECU has a 16kx8 (P)ROM but
> also has a 1kx8 Bipolar PROM in it too. I don't know exactly what
> it does but it only appears on the turbo charged engines ECU which
> have a knock sensor. It's contents look like a table so I am guessing
> that it is a lookup for the knock sensor or something.
> 
> Mine also has another NEC chip which appears to be RAM although
> the code seems to use the internal RAM of the 6802 as well. Is yours
> a 6802?
> 
> I take it a nerd novel is a databook right? I haven't come even close
> to getting a datasheet in my searching. A guy emailed me once 
> claiming that the 46510 was listed in an old Farnell catalogue and
> he was trying to get a datasheet but he never came back to me 
> with anything.
> 
> > 
> > Thanks to all for the suggestions!  Perhaps I should have been a bit
more
> > clear in my original post ... I do know that the part is not a ROM
device of
> > some sort as there is a 2764 or 27128 device on the board.  I really
doubt
> > that EEPROM devices were available for general manufacture back in the
early
> > to mid '80s in any event.  No problem though, I welcome all hunches or
leads
> > I can get, and appreciate the folks who are taking time to help! 
> > 
> > I suspect this part is likely to be a companion chip to the
microprocessor
> > ... having I/O ports, timers, interrupt controller, perhaps a small bit
of
> > RAM and maybe even an A/D converter (given the application).  While I
can't
> > seem to find it in the Hitachi nerd novels I've dug up, the fact that
I've
> > seen the part used on several different versions of the controller box
> > (dating from the mid to late '80s) I thought that perhaps there would be
a
> > data sheet with a register map somewhere out there ...
> > 
> > > 
> > > >I have been hacking around inside some old ECUs for old Audi
turbocharged engines which were built
> > > >for Audi by Hitachi.  I have been able to acquire spec sheets and
programming information for the
> > > >microprocessors (MC680X-based), but there are a couple custom LSI
devices for which I haven't been
> > > >able to obtain any sort of information.  One part that does seem to
be commonly used is a 42 (yes,
> > > >that's right!) pin DIP which has a part number of D2808C on the
cover, and another is a ceramic
> > > >substrate with 52 pins and a label HD46506.  Both parts have Hitachi
logos on them.  If anyone has
> > > >any leads as to where I could get specs I would most certainly
appreciate it!
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