RP2040 Board Design
QSPI_SD0..3, QSPI_SCLK, and QSPI_CSN.D+ → through 27 Ω series resistor → USB_DPD− → through 27 Ω series resistor → USB_DMVBUS / 5V → input of 3.3 V regulatorIOVDD, USB_VDD, VREG_VIN, and analog supply filteringQSPI_CSN low during reset/power-up so the RP2040 enters USB bootloader mode.RUN to GND.SWCLK, SWDIO, GND, and optionally 3V3/RUN.GND and 3V3 pins.GPIO25 like the Pico.