3.4.10.1 Serial Debug Com Port (FTDI)

The board features a dedicated serial port for debugging, accessible through header J35. Various interfaces can be used as a USB/Serial DBGU port bridge, such as the FTDI TTL-232R USB-to-TTL serial cable.

Figure 3-42. Serial Debug Port Schematic

The DBGU serial port uses the MCP1700/3.3V LDO to prevent any voltage higher than 3.3V to be applied on any 3.3V-only tolerant external USB-to-UART converter. For more details about the MCP1700/3.3V device, refer to the product web page.

An inexpensive level shifter solution is also implemented using two TN2106 N-channel MOSFETs.

For more details about the TN2106 device, refer to the product web page.

Table 3-28. Serial Debug Port Signal Description
PIO	Signal Name	Signal Description
PD19	DBGU_RX_PD19	UART receive data line
PD18	DBGU_TX_PD18	UART transmit data line