Datasheet

99
32059L–AVR32–01/2012
AT32UC3B
- OCD
1. Stalled memory access instruction writeback fails if followed by a HW breakpoint
Consider the following assembly code sequence:
A
B
If a hardware breakpoint is placed on instruction B, and instruction A is a memory access
instruction, register file updates from instruction A can be discarded.
Fix/Workaround
Do not place hardware breakpoints, use software breakpoints instead. Alternatively, place a
hardware breakpoint on the instruction before the memory access instruction and then sin-
gle step over the memory access instruction.
- Processor and Architecture
1. Local Bus to fast GPIO not available on silicon Rev B
Local bus is only available for silicon RevE and later.
Fix/Workaround
Do not use if silicon revision older than F.
2. Memory Protection Unit (MPU) is non functional
Memory Protection Unit (MPU) is non functional.
Fix/Workaround
Do not use the MPU.
3. Bus error should be masked in Debug mode
If a bus error occurs during debug mode, the processor will not respond to debug com-
mands through the DINST register.
Fix/Workaround
A reset of the device will make the CPU respond to debug commands again.
4. Read Modify Write (RMW) instructions on data outside the internal RAM does not
work
Read Modify Write (RMW) instructions on data outside the internal RAM does not work.
Fix/Workaround
Do not perform RMW instructions on data outside the internal RAM.
5. Need two NOPs instruction after instructions masking interrupts
The instructions following in the pipeline the instruction masking the interrupt through SR
may behave abnormally.
Fix/Workaround
Place two NOPs instructions after each SSRF or MTSR instruction setting IxM or GM in SR
6. Clock connection table on Rev B
Here is the table of Rev B