[Diy_efi] chip P/N
WSCowell at aol.com
WSCowell at aol.com
Sun Dec 26 10:25:37 GMT 2004
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Hi Tom,
Well, I can help with some info on these parts but I stress only from a
generic digital hardware engineer's perspective, as I am no specialist in the
world of fuel injection. That's why I'm on this forum in the first place - to
find out more for my self.
The HD63B03 part is a pretty standard part. It is an integrated
microcontroller with all the characteristics of the Motorola 6800, but built under
licence in CMOS technology (lower power drain etc) and this is the significance of
the "63" bit.
The "B" relates to the clock speed, it was the fastest of the series, with a
clock speed of 8MHz. The "03" bit says all you need to know about what
other peripheral devices were integrated onto the chip, such as input/ouput
ports, timer, analog/digital convertor etc. I used to design kit with the
HD63B03, but I can't remember where my data book is now. The information on this
device should certainly be out there in the public domain somewhere.
Go out and look with a search engine for "device data", "Hitachi
microcontroller" and similar phrases. I am sure you'll get a hit.
The 27C256 is a bog standard EPROM and the label will cover a window which
gives access to the chip for UV light to erase it. The "12.5v PGM" bit means
that the programming voltage is 12.5 volts. If set to the 5volt rail
instead, the chip functions as a read-only device. When you raise the voltage on
the relevant pin on the device (see data sheet!) to 12.5 volts, it becomes
programmable in accordance with then-standard industry normal programming, timing
etc norms. This was all standard in EPROM programmers of the day. No
reason to believe it has changed since then.
As for whether you can replace it with another device to allow modification
of data on the fly, (I quite agree it's a pain in the a**e repeating the
"proram/check/erase/reprogram" routine for development purposes) I remember you
could get "instant EPROM" devices consisting of a static RAM chip of equivalent
memory size (e.g. a 61256) to plug-in to the EPROM socket but you still need
the microcontroller itself to have firmware routines built-in to enable it
to communicate with an external device (e.g. RS-232 serial port) AND you need
the microcontroller itself to be designed from a hardware point of view to
allow read/write operations to the memory device sitting in the EPROM socket.
I doubt the 7A ECU has that - if it did, it would have a flash device in
there instead of the old EPROM technology.
I finished working as a hardware designer 14 years ago, and all the above
was current technology at the time. Flash memory devices were just coming in.
Manufacturers will not usually use state of the art devices because low
component cost is a primary element in the profit you get from building
electronic equipment!
Hope this helps. Good luck!
Will
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<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; charset=3DUS-ASCII">
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e_document=20
face=3DArial color=3D#000000 size=3D2>
<DIV>Hi Tom,</DIV>
<DIV> </DIV>
<DIV>Well, I can help with some info on these parts but I stress only from a=
=20
generic digital hardware engineer's perspective, as I am no specialist in th=
e=20
world of fuel injection. That's why I'm on this forum in the first pla=
ce -=20
to find out more for my self.</DIV>
<DIV> </DIV>
<DIV>The HD63B03 part is a pretty standard part. It is an integrated=20
microcontroller with all the characteristics of the Motorola 6800, but built=
=20
under licence in CMOS technology (lower power drain etc) and this is th=
e=20
significance of the "63" bit.</DIV>
<DIV> </DIV>
<DIV>The "B" relates to the clock speed, it was the fastest of the series, w=
ith=20
a clock speed of 8MHz. The "03" bit says all you need to know about wh=
at=20
other peripheral devices were integrated onto the chip, such as input/ouput=20
ports, timer, analog/digital convertor etc. I used to design kit with=20=
the=20
HD63B03, but I can't remember where my data book is now. The informati=
on=20
on this device should certainly be out there in the public domain=20
somewhere.</DIV>
<DIV> </DIV>
<DIV>Go out and look with a search engine for "device data", "Hitachi=20
microcontroller" and similar phrases. I am sure you'll get a hit.</DIV=
>
<DIV> </DIV>
<DIV>The 27C256 is a bog standard EPROM and the label will cover a window wh=
ich=20
gives access to the chip for UV light to erase it. The "12.5v PGM" bit=
=20
means that the programming voltage is 12.5 volts. If set to the 5volt=20=
rail=20
instead, the chip functions as a read-only device. When you raise the=20
voltage on the relevant pin on the device (see data sheet!) to 12.5 volts, i=
t=20
becomes programmable in accordance with then-standard industry normal=20
programming, timing etc norms. This was all standard in EPROM programm=
ers=20
of the day. No reason to believe it has changed since then.</DIV>
<DIV> </DIV>
<DIV>As for whether you can replace it with another device to allow modifica=
tion=20
of data on the fly, (I quite agree it's a pain in the a**e repeating the=20
"proram/check/erase/reprogram" routine for development purposes) I remember=20=
you=20
could get "instant EPROM" devices consisting of a static RAM chip of equival=
ent=20
memory size (e.g. a 61256) to plug-in to the EPROM socket but you still need=
the=20
microcontroller itself to have firmware routines built-in to enable it to=20
communicate with an external device (e.g. RS-232 serial port) AND you need t=
he=20
microcontroller itself to be designed from a hardware point of view to allow=
=20
read/write operations to the memory device sitting in the EPROM socket. =
; I=20
doubt the 7A ECU has that - if it did, it would have a flash device in there=
=20
instead of the old EPROM technology.</DIV>
<DIV> </DIV>
<DIV>I finished working as a hardware designer 14 years ago, and all the=20
above was current technology at the time. Flash memory devices we=
re=20
just coming in. Manufacturers will not usually use state of the art=20
devices because low component cost is a primary element in the profit you ge=
t=20
from building electronic equipment!</DIV>
<DIV> </DIV>
<DIV>Hope this helps. Good luck!</DIV>
<DIV> </DIV>
<DIV>Will</DIV></FONT></BODY></HTML>
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