Datasheet

672
32133D–11/2011
UC3D
31.3.7.1 Cyclic Redundancy Check (CRC)
The MSU can be used to automatically calculate the CRC of a block of data in memory. The
MSU will then read out each word in the specified memory block and report the CRC32-value in
an MSU register.
31.3.7.2 NanoTrace
The MSU additionally supports NanoTrace. This is a 32-bit AVR-specific feature, in which trace
data is output to memory instead of the AUX port. This allows the trace data to be extracted by
the debugger through the SAB, enabling trace features for aWire- or JTAG-based debuggers.
The user must write MSU registers to configure the address and size of the memory block to be
used for NanoTrace. The NanoTrace buffer can be anywhere in the physical address range,
including internal and external RAM, through an EBI, if present. This area may not be used by
the application running on the CPU.
31.3.8 AUX-based Debug Features
Utilizing the Auxiliary (AUX) port gives access to a wide range of advanced debug features. Of
prime importance are the trace features, which allow an external debugger to receive continuous
information on the program execution in the CPU. Additionally, Event In and Event Out pins
allow external events to be correlated with the program flow.
Debug tools utilizing the AUX port should connect to the device through a Nexus-compliant Mic-
tor-38 connector, as described in the AVR32UC Technical Reference manual. This connector
includes the JTAG signals and the RESET_N pin, giving full access to the programming and
debug features in the device.