95 LT1 PCM (16188051) uses a 16202476 MCU !!

[Tom Hussey]

Thanks Ken...I slipped up here. The event flash is a 'F010 1M bit/128K X
8 and the timing is a 'F512 for 64K X 8.
I wrote a routine to dump through the ALDL. That only gave me the first
64K page of the timing. Someone on the inside gave me the GM files used
to flash the ECM. That gave me the rest of what I need to complete the
disassembly. So far I have many hundreds of hours into commenting the
code. What do you call this system P? just so I know.

-Tom

Ken Kelly wrote:
> 
> Tom,
>         I'm confused. I thought the 96 LT1 PCM went to a 1024K Flash
> on the T side and
> used the same 512K Flash on the E side. I have included recognition of
> the 96
> chips in my editor. I don't have a set of the 97 prom images, so I
> haven't tried
> them. I thought the 97 and 96 were the same. If you have data location
> for these
> chips I'll build them into the editor. The checksum locations for the
> 95 seem to
> work fine for the 96 E side.
> 
>         Did you socket your PCM or dump the data through the ALDL
> port? I need to get
> you together with Dave Hempstead. Hes doing the same disassemble for
> the 95.
> 
>                 Ken
> 
> Tom Hussey wrote:
> >
> > Hi,
> >
> > I am sure the 16202476 processor is a MC68HC11F1. All the I/O port
> > addresses line up with the data sheet. I can see from my disassembly
> of
> > the '97 Camaro that the SPI port is manipulated on both processors
> for
> > redundancy and how the data comm scheme works. Other chips I have
> > identified are MC68HC58 for OBDII data comm, mc33291 or mc33298 for
> > octal drivers. I have decoded the section that drives these chips.
> > Anyone with part numbers? Flash used is 512K on event side and 64K
> on
> > the timing side.
> > The OBD chip is at $1060 and $1061 if anyone is interested.
> >
> > -Tom
> >
> > Ken Kelly wrote:
> > >
> > > Ludis,
> > >
> > >         Do you know which Variant of the HC11 this is?
> > >
> > >         The original posting was to try to identify which variety
> > > of 68HC11 is in the 16202476? We are disassembling the 8051
> > > EEprom, and the memory maps are different in the different
> > > variants. We thought it was a 68HC11K4, but David Cooley,
> > > thought that it was a 68HC11F1. Davids comments were based
> > > on a P6 and I need to look at my board tonight, but I seem
> > > to remember seeing P5 in the silkscreening.
> > >
> > >                 Ken
> > >
> > > Ludis Langens wrote:
> > > >
> > > > "David A. Cooley" wrote:
> > > > >
> > > > > I have 2 unidentifiable chips, 52 pin PLCC's, one is 56597 and
> > > labeled
> > > > > Delco, the other is labeled NCR and is 129170
> > > >
> > > > The ECM for the '95 2.2 L4 "4", 16191947, also uses a 16202476
> and a
> > > > 56597.  The 16191947  uses a MEMCAL with a 27_512.  I assume the
> > > 56597
> > > > is a two injector version of the buffer / I/O port / peak+hold
> > > > controller which all the P4's use.
> > > >
> > > > Check the circuitry around the 56597.  Are there two diodes, two
> > > 1.8K
> > > > resistors, and two polarized capacitors, all hooked together and
> to
> > > two
> > > > pins of the 56597?  The old single injector controller uses
> these
> > > parts
> > > > to implement a voltage doubler.
> > > >
> > > > Other chips in the 16191947 are:
> > > >      34987  O2 amp
> > > >      34992  Power supply
> > > >      34993  IAC driver
> > > >   16045152  CD4011 quad NAND (?)
> > > >      45153  CD4051 mux (?)
> > > >      64606  ALDL interface
> > > >      04891  ???
> > > >      89551  ???
> > > >   16132083  ???
> > > >   16206550  ???
> > > >
> > > > --
> > > > Ludis Langens                               ludis (at) cruzers
> (dot)
> > > com
> > > > Mac, Fiero, & engine controller goodies:
> > > http://www.cruzers.com/~ludis/