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--- 20b:software-keyscanner [2008/07/23 19:33]
newell
+++ 20b:software-keyscanner [2008/07/28 19:18] (current)
newell Updated code to fix ARM->Thumb bug, added readme contents
@@ Line 1: / Line 1: @@
+{{:20b:scancode_demo.tgz|}}===== Keyscanner / Display Tester =====
+==== Description ====
+A simple SRAM resident keyscan/display test.
+==== Usage ====
+Boot calc into test mode (to allow stock firmware to configure and init the chip),
+connect a debugger, halt the chip, download the image, and let 'er rip.
+It'll probably corrupt anything you had in ram before.
+==== Download link ====
+ {{20B:scancode_demo.tgz}}
+==== Readme file ====
+This is a bare bones example program for the HP20B. It runs from ram, in
+Thumb mode, and assumes that the  stock firmware has completely
+initialized the hardware.
+Build the code.  You'll want to modify the path to gcc in the makefile.
+Once compiled and linked, you'll have a .hex and .elf file. Use
+whichever your debugger perfers.  Entry point is 0x2ff000.  Startup is
+in ARM mode and switches to Thumb when it hits main, so be sure the core
+is in ARM mode to start.
+I'm using OCD Commander under win2k, so I like to start by placing the
+calc in self test mode, turn on TSys and verify that the alpha display
+is scrolling.  I start OCD Commander, configure the connection, and then
+stop the target.  I check that the scroll has stopped.  I like to
+restart the target and see the scroll start again to verify my
+connection.  Configure as little endian, "reset", "down" to download
+the image file, and then "go" to run it.
+I've also tried OpenODC.  Once connected, I do a "soft_reset_halt", then
+a "load_image scancode_demo.hex", followed by a "resume 0x2ff000".
+Yes, the code is ugly.  Fix it at your own risk.  Consider it nothing
+more than a toy to demonstrate that we know a little about the hardware.
+Happy HP Hacking!

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