Tool/software: Code Composer Studio
Hello everybody,
I have problems with the JTAG communication.
I have the CC3220MOD module mounted on a custom board and I am using the XDS110 USB Debug Probe for JTAG debugging.The JTAG connects to a 14-pin TI connector, using the CTI-20 to TI 14 pin adaptor.
The controller does not respond and I get the following error when I run the JTAG Test Connection:
The value is '-233' (0xffffff17).
The title is 'SC_ERR_PATH_BROKEN'.
The explanation is:
The JTAG IR and DR scan-paths cannot circulate bits, they may be broken.
An attempt to scan the JTAG scan-path has failed.
The target's JTAG scan-path appears to be broken
with a stuck-at-ones or stuck-at-zero fault.
I found some threads concerning this error:
All these suggest that there could be hardware problem with my system, but I cannot figure it out.
For this reason I started to debug the JTAG connection and I saw that the XDS110 Debug Probe sends the data and the clock on the right lines (TDI, TCK) during the Test Connection but it does not receive anything from the chip (TDO). On my schematic pin SOP2 is pulled down with a 2.7 k resistor, while SOP1 and SOP0 are unconnected. Is this configuration correct or should I have pull-downs for all three SOP pins? (The CC3220MOD datasheet mentions that there are pull-down resistors for those pins inside the module.The typical application schematic in CC3220MOD datasheet shows no pull-downs.)
Can anyone please suggest some (other) reasons for which the chip is not responsive? (I have already tested 2 boards with same results, I don´t think that both of them have defective chips since they are factory made).
Or, please suggest where should I look or how to debug it in order to find the cause of this problem.
Otherwise, is there another way to enable the JTAG communication or to "wake up" the module?
Thank you very much for your time.
Cristian
