Flash; Uart - Espressif Systems ESP32-C3 Series Hardware Design Manuallines

3 PCB Layout Design
Figure 20: ESP32­C3 Family PCB Stack­up Design

3.6 Flash

Place the reserved serial resistor on the SPI interface close to the chip side. Route the SPI traces on the inner
layer (e.g., the third layer) whenever possible. Add ground copper and ground vias around the clock and data
traces of SPI separately.
Figure 21: ESP32­C3 Family Flash Layout

3.7 UART

The series resistor on the U0TXD line needs to be placed close to the chip and away from the crystal. The
U0TXD and U0RXD traces on the top layer should be as short as possible, surrounded by ground copper and
ground vias.
Espressif Systems 23
ESP32-C3 Family Hardware Design Guidelines V0.5
Submit Documentation Feedback