https://devzone.nordicsemi.com/f/nordic-q-a/85613/can-t-program-nrf5340-when-powered-by-vbusHi there, We are developing on the NRF5340, and have a question regarding programing. You cannot program a core, while Nordic is only powered by Vbus. When I give Vbus power to Nordic, the programmer is able to see him but It is impossible flash , buten-USTelligent Community 13Thu, 10 Mar 2022 11:21:42 GMThttps://devzone.nordicsemi.com/thread/357378?ContentTypeID=1Thu, 10 Mar 2022 11:21:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:19657d95-0b5d-489f-9e98-354bad23eb14Jared<p>Hi,</p> <p></p> [quote user=""]You cannot program a core, while Nordic is only powered by Vbus.<br />When I give Vbus power to Nordic, the programmer is able to see him but It is impossible flash , but not why?[/quote] <p><span>In Normal mode (VDDH &amp; VDD not tied) you need to supply the VDD to program the board. VBUS only supplies&nbsp;the USB interface.</span><span>&nbsp;At least you have to connect the VDDH interface to VBUS(high voltage mode), if you&#39;re only supplying via VBUS.</span></p> <h3><a href="https://infocenter.nordicsemi.com/topic/ps_nrf5340/chapters/usbregulator/doc/usbregulator.html?cp=3_0_0_3_7">USBREG — USB regulator control</a></h3> <h3><a href="https://infocenter.nordicsemi.com/topic/ps_nrf5340/regulators.html?cp=3_0_0_3_6">REGULATORS — Regulator control</a></h3> <p><span>regards</span></p> <p><span>Jared&nbsp;</span></p><div style="clear:both;"></div>