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20b:software-keyscanner [2008/07/23 19:33]
20b:software-keyscanner [2008/07/28 19:18] (current)
newell Updated code to fix ARM->Thumb bug, added readme contents
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 +{{:​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!
20b/software-keyscanner.txt · Last modified: 2008/07/28 19:18 by newell