May I use only 2-wire SWD (SWCLK, SWDIO), Vcc (from target) and GND to debug target QN9080 system using QN9080 DK board

[yuanteliu]

Due to available pins in our system, There are only 3 spare wires available from the connector of our system for debugger use. It is planned to be Vcc (from target system) SWCLK, and SWDIO. It did work well in our previous project using other Cortex M0 MCU (nRF51822). Can someone teach me if it is OK or not? (it is known that some debugging feature will be missing if no SWO signal.

Regards

[stephanie_m]

Hello, 

Yes, you can use only those, maybe you want to consider using also the Reset pin during your debug. 

Regards, 
Estephania

[yuanteliu]

Thanks for your flash response and reminding.

If we need hardware reset, it should be. Our plan is to use global reset

issued from debugger. Any comments to this idea?

Best Regards

estephania_martinez <admin@community.nxp.com> 於 2019年1月31日 週四 上午7:57寫道：

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Re: May I use only 2-wire SWD (SWCLK, SWDIO), Vcc (from target) and GND to

debug target QN9080 system using QN9080 DK board

reply from Estephania Martinez

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[gerardo_rodriguez]

Hi,

You might want to consider using the hardware reset if you plan to put the QN9080 into powerdown mode. In this mode, the debug module and SWD pins will be disabled and you won't be able to communicate to the device unless you issue a hardware reset to wake the device.

Regards.