13
32000D–04/2011
AVR32
EM - Exception mask
When this bit is set, exceptions are masked. Exceptions are enabled otherwise. The bit is auto-
matically set when exception processing is initiated or Debug Mode is entered. Software may
clear this bit after performing the necessary measures if nested exceptions should be supported.
This bit is set at reset.
I3M - Interrupt level 3 mask
When this bit is set, level 3 interrupts are masked. If I3M and GM are cleared, INT3 interrupts
are enabled. The bit is automatically set when INT3 processing is initiated. Software may clear
this bit after performing the necessary measures if nested INT3s should be supported. This bit is
cleared at reset.
I2M - Interrupt level 2 mask
When this bit is set, level 2 interrupts are masked. If I2M and GM are cleared, INT2 interrupts
are enabled. The bit is automatically set when INT3 or INT2 processing is initiated. Software
may clear this bit after performing the necessary measures if nested INT2s should be supported.
This bit is cleared at reset.
I1M - Interrupt level 1 mask
When this bit is set, level 1 interrupts are masked. If I1M and GM are cleared, INT1 interrupts
are enabled. The bit is automatically set when INT3, INT2 or INT1 processing is initiated. Soft-
ware may clear this bit after performing the necessary measures if nested INT1s should be
supported. This bit is cleared at reset.
I0M - Interrupt level 0 mask
When this bit is set, level 0 interrupts are masked. If I0M and GM are cleared, INT0 interrupts
are enabled. The bit is automatically set when INT3, INT2, INT1 or INT0 processing is initiated.
Software may clear this bit after performing the necessary measures if nested INT0s should be
supported. This bit is cleared at reset.
GM - Global Interrupt Mask
When this bit is set, all interrupts are disabled. This bit overrides I0M, I1M, I2M and I3M. The bit
is automatically set when exception processing is initiated, Debug Mode is entered, or a Java
trap is taken. This bit is automatically cleared when returning from a Java trap. This bit is set
after reset.
Table 2-5.
Mode bit settings
M2
M1
M0
Mode
1
Non Maskable Interrupt
1
0
Exception
1
0
1
Interrupt level 3
1
0
Interrupt level 2
0
1
Interrupt level 1
0
1
0
Interrupt level 0
0
1
Supervisor
0
Application