I am currently trying to get my Bus Blaster v4.1a to work. I want to use openocd to communicate with a device over JTAG. The device that I want to communicate with is a Qualcomm_qca4531.
First of all let me show you the command that I enter in the terminal just in case that I am already doing something wrong here:
~/openocd/tcl$ sudo openocd -f interface/ftdi/dp_busblaster.cfg -f target/qualcomm_qca4531.cfg
The 2 config files that I am using were already provided by openocd and can be found here:
The error that I am receiving from OpenOCD right after entering the command is the following.
Open On-Chip Debugger 0.10.0+dev-00936-g0a13ca1a (2019-10-10-09:36) Licensed under GNU GPL v2 For bug reports, read http://openocd.org/doc/doxygen/bugs.html Info : If you need SWD support, flash KT-Link buffer from https://github.com/bharrisau/busblaster and use dp_busblaster_kt-link.cfg instead adapter speed: 2000 kHz Info : auto-selecting first available session transport "jtag". To override use 'transport select <transport>'. qca4531_ddr2_550_550_init Info : Listening on port 6666 for tcl connections Info : Listening on port 4444 for telnet connections Info : clock speed 2000 kHz Error: JTAG scan chain interrogation failed: all zeroes Error: Check JTAG interface, timings, target power, etc. Error: Trying to use configured scan chain anyway... Error: qca4531.cpu: IR capture error; saw 0x00 not 0x01 Warn : Bypassing JTAG setup events due to errors Info : Listening on port 3333 for gdb connections
I already checked a few things:
I checked if any of the JTAG Pins is shortened to gnd or vcc. They aren't.
I also tried to use urJTAG to communicate with the device, it doesn't work either but I receive a different error: TDO seems to be stucked at 1.
I also checked if I connected the right pins. I have 6 pins that I have to connect. VCC, GND, TMS, TCK, TDI and TDO. There are only these 4 JTAG pins on the board but after a little research I found out that I only need these 4 pins, TRST and other JTAG pins are optional so I think there should be everything fine with the connection.
I can also confirm that the Bus Blaster supports the same voltage levels as my target device. (3.3V)
Can you think of any other reason why I get the error mentioned above?
Is it possible that JTAG is deactivated on the target device? I tried to find out what openocd output looks like when JTAG is deactivated but I can't find anything helpfull.
Thanks to everyone in advance.