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32000D–04/2011
AVR32
8.3.2
Description of events in AVR32B
8.3.2.1
Reset Exception
The Reset exception is generated when the reset input line to the CPU is asserted. The Reset
exception can not be masked by any bit. The Reset exception resets all synchronous elements
and registers in the CPU pipeline to their default value, and starts execution of instructions at
address 0xA000_0000.
SR = reset_value_of_SREG;
PC = 0xA000_0000;
All other system registers are reset to their reset value, which may or may not be defined. Refer
to the Programming Model chapter for details.
8.3.2.2
OCD Stop CPU Exception
The OCD Stop CPU exception is generated when the OCD Stop CPU input line to the CPU is
asserted. The OCD Stop CPU exception can not be masked by any bit. This exception is identi-
cal to a non-maskable, high priority breakpoint. Any subsequent operation is controlled by the
OCD hardware. The OCD hardware will take control over the CPU and start to feed instructions
directly into the pipeline.
RSR_DBG = SR;
RAR_DBG = PC;
SR[M2:M0] = B’110;
SR[R] = 0;
SR[J] = 0;
SR[D] = 1;
SR[DM] = 1;
SR[EM] = 1;
SR[GM] = 1;
8.3.2.3
Unrecoverable Exception
The Unrecoverable Exception is generated when an exception request is issued when the
Exception Mask (EM) bit in the status register is asserted. The Unrecoverable Exception can not
be masked by any bit. The Unrecoverable Exception is generated when a condition has
occurred that the hardware cannot handle. The system will in most cases have to be restarted if
this condition occurs.
RSR_EX = SR;
RAR_EX = PC of offending instruction;
SR[R] = 0;
SR[J] = 0;
SR[M2:M0] = B’110;
SR[EM] = 1;
SR[GM] = 1;
PC = EVBA + 0x00;