David Kelly <[email protected]> wrote: >> I understand that JTAg, thanks to its very nature, allows to chain >> devices, allowing to talk with any one dvice from a single JTAG port. > > In practice I don't think the Dragon supports that.
Of course, it does. We aren't in MSP430 land here... (From what I've heard, MSP430 has a crippled and incomplete JTAG implementation that doesn't allow chaining.) You need AVRDUDE 5.6, where you can specify -x jtagchain UB,UA,BB,BA. UB is "units before", UA is "units after", BB is "bits before", BA is "bits after". Each AVR shifts by 4 bits within the JTAG chain. So if you've got two AVRs in one chain, depending on which AVR you are talking to, you use "-x jtagchain 0,1,0,4", or "-x jtagchain 1,0,1,4". The only disadvantage of that solution is that you cannot debug both targets simultaneously. AVR Studio offers a similar setup box somewhere. -- cheers, J"org .-.-. --... ...-- -.. . DL8DTL http://www.sax.de/~joerg/ NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-) _______________________________________________ AVR-chat mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/avr-chat
