From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Schweigstill Date: Thu, 13 Sep 2007 17:15:49 +0200 Subject: [U-Boot-Users] R: Booting with attached BDI butnot alone (onlyICTRL remained in BDI cfg) In-Reply-To: <46E94835.40003@smiths-aerospace.com> References: <46E945A8.90308@schweigstill.de> <46E94835.40003@smiths-aerospace.com> Message-ID: <46E95425.2030109@schweigstill.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hello! Jerry Van Baren schrieb: > Sounds like his board was damaged by operator error (improperly > connecting to the BDI connector). My guess is that the pullup resistor > lost its smoke. I agree that the board may have been damaged by the operator. But the pull-up resistor won't be damaged except from very high voltage. Attaching a debug interface in the wrong direction probably may destroy it if it gets its power supply from the target. If it has its own supply (or gets it via USB from a PC) it can be possibly that either negative voltages (target GND connected to debugger VCC) or high voltages (target VCC connected to debugger GND) may be applied to the JTAG/BDM signals on the target. Such voltages may cause small defects to the silicon which show strange behaviour afterwards. Regards Andreas Schweigstill -- Dipl.-Phys. Andreas Schweigstill Schweigstill IT | Embedded Systems Schauenburgerstra?e 116, D-24118 Kiel, Germany Phone: (+49) 431 5606-435, Fax: (+49) 431 5606-436 Mobile: (+49) 171 6921973, Web: http://www.schweigstill.de/