please dont rip this site

How does the Microchip ICD Work?

Myke Predko says:

When I was doing the second edition of my PICmicro microcontroller book, I did some hacking of the ICD Interface and I found that in "ICD mode", all the hardware registers could be written to, but any changes to them didn't take effect until *after* a "return" instruction was executed.

While the PICmicro MCU was in ICD mode the only hardware resources that could be accessed correctly were:

  1. RB6/RB7 via 0x0106. Only the Programming "Data" pin's TRIS bit could be changed. The Clock bit stayed in input mode.
  2. Program memory flash read/write controls.
  3. ICKBUG and BIGBUG (according to DS51242A - I didn't have this document when I was playing around with it so I called the registers "Reserve_E" and "Reserve_F") could be read and written before executing a "return" to return to the executing application.
  5. All File Registers

If you are interested in seeing what I found, Take a look at pages 650 to 652 of the book. On the CD-ROM, in the EMU-II directory, you will find the source code that I created from the 256 instructions inserted into the ICD by the controller.


file: /Techref/microchip/icdhow.htm, 2KB, , updated: 2008/4/10 16:56, local time: 2024/7/17 10:36,

 ©2024 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?
Please DO link to this page! Digg it! / MAKE!

<A HREF=""> How the Microchip ICD Works</A>

After you find an appropriate page, you are invited to your to this massmind site! (posts will be visible only to you before review) Just type a nice message (short messages are blocked as spam) in the box and press the Post button. (HTML welcomed, but not the <A tag: Instead, use the link box to link to another page. A tutorial is available Members can login to post directly, become page editors, and be credited for their posts.

Link? Put it here: 
if you want a response, please enter your email address: 
Attn spammers: All posts are reviewed before being made visible to anyone other than the poster.
Did you find what you needed?


Welcome to!

Site supported by
sales, advertizing,
& kind contributors
just like you!

Please don't rip/copy
(here's why

Copies of the site on CD
are available at minimal cost.

Welcome to!