[Diy_efi] Motorola 68HC11

Kent Martin kentmartin at froggy.com.au
Thu Jun 20 14:14:01 GMT 2002


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Hi,
I have worked with these little suckers a fair bit and I did one
project where I wrote to the bootstrap register (I think) while running =
in
external memory and then reset the micro to run code internal to the =
chip
to program the external flash memory. So I think the answer to your =
question is no.
Writes to this register only become active after reset.
FYI, if you using the HC11 for an EFI system you would do well to pick =
another micro.
I have built an efi system with the Hc11 before (in assembler) and it is =
not fun.
Many more suitable micros are available for this type of application and =
I am=20
investigating a few of them now. If you are interested let me know.

Kent.
  ----- Original Message -----=20
  From: Matt Donohoe=20
  To: diy_efi at diy-efi.org=20
  Sent: Sunday, June 16, 2002 12:49 AM
  Subject: [Diy_efi] Motorola 68HC11


  Hi,

  Just wondering something, can the 68HC11 be changed from expanded to I =
guess you would call it "bootstrap" mode on the fly by the use of a =
register flag?

  If so, which flag, if no, which model of chips allows this?

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<DIV><FONT face=3DArial size=3D2>Hi,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>I have worked with these little suckers =
a fair bit=20
and I did one</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>project where I wrote to the bootstrap =
register (I=20
think) while running in</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>external&nbsp;memory&nbsp;and =
</FONT><FONT=20
face=3DArial size=3D2>then reset the micro to run code internal to the=20
chip</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>to program the external flash memory. =
So I think=20
the answer to your question is no.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Writes to this register only become =
active after=20
reset.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>FYI, if you using the HC11 for an EFI =
system you=20
would do well to pick another micro.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>I have built an efi system with the =
Hc11 before=20
(in&nbsp;assembler) and it is not fun.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Many more suitable micros are available =
for this=20
type of application and I am </FONT></DIV>
<DIV><FONT face=3DArial size=3D2>investigating a few of them now. If you =
are=20
interested let me know.</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Kent.</FONT></DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: =
0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
  <DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
  <DIV=20
  style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
  <A href=3D"mailto:donohoem at iprimus.com.au" =
title=3Ddonohoem at iprimus.com.au>Matt=20
  Donohoe</A> </DIV>
  <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
href=3D"mailto:diy_efi at diy-efi.org"=20
  title=3Ddiy_efi at diy-efi.org>diy_efi at diy-efi.org</A> </DIV>
  <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Sunday, June 16, 2002 =
12:49=20
AM</DIV>
  <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [Diy_efi] Motorola =
68HC11</DIV>
  <DIV><BR></DIV>
  <DIV><FONT face=3DArial size=3D2>Hi,</FONT></DIV>
  <DIV>&nbsp;</DIV>
  <DIV><FONT face=3DArial size=3D2>Just wondering something, can the =
68HC11 be=20
  changed from expanded to I guess you would call it "bootstrap" mode on =
the fly=20
  by the use of a register flag?</FONT></DIV>
  <DIV>&nbsp;</DIV>
  <DIV><FONT face=3DArial size=3D2>If so, which flag, if no, which model =
of chips=20
  allows this?</FONT></DIV></BLOCKQUOTE></BODY></HTML>

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