XMEGA A4U [DATASHEET]
Atmel-8387G-AVR-ATxmega16A4U-34A4U-64A4U-128A4U-Datasheet_03/2014
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31.
Programming and Debugging
31.1
Features
Programming
External programming through PDI interface
Minimal protocol overhead for fast operation
Built-in error detection and handling for reliable operation
Boot loader support for programming through any communication interface
Debugging
Nonintrusive, real-time, on-chip debug system
No software or hardware resources required from device except pin connection
Program flow control
Go, Stop, Reset, Step Into, Step Over, Step Out, Run-to-Cursor
Unlimited number of user program breakpoints
Unlimited number of user data breakpoints, break on:
Data location read, write, or both read and write
Data location content equal or not equal to a value
Data location content is greater or smaller than a value
Data location content is within or outside a range
No limitation on device clock frequency
Program and Debug Interface (PDI)
Two-pin interface for external programming and debugging
Uses the Reset pin and a dedicated pin
No I/O pins required during programming or debugging
31.2
Overview
The Program and Debug Interface (PDI) is an Atmel proprietary interface for external programming and on-chip
debugging of a device.
The PDI supports fast programming of nonvolatile memory (NVM) spaces; flash, EEPOM, fuses, lock bits, and the
user signature row.
Debug is supported through an on-chip debug system that offers nonintrusive, real-time debug. It does not require any
software or hardware resources except for the device pin connection. Using the Atmel tool chain, it offers complete
program flow control and support for an unlimited number of program and complex data breakpoints. Application
debug can be done from a C or other high-level language source code level, as well as from an assembler and
disassembler level.
Programming and debugging can be done through the PDI physical layer. This is a two-pin interface that uses the
Reset pin for the clock input (PDI_CLK) and one other dedicated pin for data input and output (PDI_DATA). Any
external programmer or on-chip debugger/emulator can be directly connected to this interface.
32.
Pinout and Pin Functions
pin can have several alternate functions. This will depend on which peripheral is enabled and connected to the actual
pin. Only one of the pin functions can be used at time.
32.1
Alternate Pin Function Description
The tables below show the notation for all pin functions available and describe its function.