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IMPORTANT: enter the case-INsensitive alphabetic (no numbers) code AND WRITE SOME SHORT summary of changes (below) if you are saving changes. (not required for previewing changes). Wiki-spamming is not tolerated, will be removed, so it does NOT even show up in history. Spammers go away now. Visit Preferences to set your user name Summary of change: '''How to Debug software?''' - write good code that is easy to understand - try to explain your code in comments (unless trivial) - log to serial port and examine the output: - make some characteristic numbers available (counters, histograms) in mem or serial port (see benchstats) - go through your program in AtMega/AvrStudio (note that this won't surely show the overflows!) - make someone audit your code There is also AtMega In Circuit Emulation possibility built into the AtMega128 (not sure in what way it is better for debugging than Avr Studio. It could probably be used for more detailed circuit-testing than from pure firware-based hw-test.) NEW INFO: A guy made a very simple and cheap (around 30 Euro) board with AtMega163, that works with AtMega/AvrStudio. A few still available here: http://www.x-dsl.hu/genboard/ Write a note here if you don't need it just now, but interested in it for later. Some more info: ---- '''Where to buy JTAG ICE?''' We had a few dozens of AVR JTAG. You can always buy one from atmel.com somewhat more expensive. Our developers never actually used it (firmware upload via ISP, and BootLoader, debug via serial.) ---- '''Howto make JTAG ICE (Compatible to Atmel AVR JTAG*ICE)''' You can search for Freeice on internet. ATmega163 (or Atmega16, need bootloader fix!!) 7.3728 Crystal Standard UART Serial Driver (MAX232, etc) VREF (pin 29) to VCC ADC2 (pin35) to VCC PD3 pull-down resistor 4k7 Connect some ATmega to your ICE TDO - PB6(pin12) to target TDO TDI - PB5(pin1) to target TDI TMS - PB1(pin41) to target TMS TCK - PB7(pin3) to target TCK PB3(pin43) to LED (other side of LED to VCC) this is "JTAG Activity" Program with bootice.rom see source bootice.bas (AVR Basic) use Pony Prog (notice bootloader is for m163 only) Set Fuses: BOOTSZ, BOOTRST all programmed, Clock all non-programmed see Pony Prog screenshot Connect your ATmega to COM port Start AVRStudio 4 Launch AVRPROG Select "Program Files\Atmel\AVR Tools\JTAGICE\Upgrade.ebn" as Flash file Program Flash, close AVRPROG Program Fuses using Pony Prog so that BOOTRST is not programmed see Pony Prog screenshot In AVRStudio 4, Tools-JTAGICE you should see following screenshot Congratulations you have AVRStudio connected to JTAGICE! Go ahead and use your own JTAGICE ! ----- A guy published his success with a simple and cheap ice: AtMega/JTaG/Hungarian ----- It works! I used a Mega16 as the Mega163 is an obsolete part. Use the special bootloader 'bootice16.rom' from http://www.case2000.com/JtagIce/ This bootloader has one problem: When you load the firmware with AVRPROG, it shows an verify error. Ignore this, it will work anyway. Don't play around with AVRPROG after this, it may damage your firmware. Simply reset the bootrst flag with ponyprog afterwards and you are done. It should now work with AVRstudio 4 from scratch. If not, erase the chip and repeat the whole procedure carefully. As the JTAG interface gets it's supply from the target, ist is possible to debug 3,3V parts, but it may be that the RS232 coverter (MAX232) does not work with 3,3V. Use another part in this case (MAX3323 may work, but not tested). Everything you need (including sources and schematics) is inside the archive http://home.sch.bme.hu/~cell/atmel/AVR_JTAG/avr_jtag.zip Original bootice site is at http://www.case2000.com/JtagIce/bootice.html Many thanks to Antti Lukats and Marcell Gál. Good luck! ----- A command-line based DOS..XP program for the Atmel or clone JTAG: http://www.avrfreaks.com/Tools/showtools.php?ToolID=470 ---- '''See also''' * [http://www.amontec.com/ ARM jtag] Optional: Add document to category: Wiki formatting: * is Bullet list ** Bullet list subentry ... '''Bold''', ---- is horizontal ruler, <code> preformatted text... </code> See wiki editing HELP for tables and other formatting tips and tricks.