4.5 UPDI Interface

The Unified Program and Debug Interface (UPDI) is a Microchip proprietary interface for external programming and on-chip debugging of a device.

Programming and debugging are performed using the UPDI Physical interface (UPDI PHY), which is a UART-based half-duplex 1-wire interface for data reception and transmission. It uses the Reset line to detect the debugger probe.

Figure 4-8. Standard UPDI Header

Single-wire interface can be enabled by setting a fuse or by 12V programming, which disables the reset functionality. Not all programming tools are capable of generating this voltage.

Note: Refer to the respective programmer user guide for more information about the capabilities and physical interface of UPDI.