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107
8210C–AVR–09/11
Atmel AVR XMEGA D
10.7
Interrupt vector locations
shows reset and Interrupt vectors placement for the various combina-
tions of BOOTRST and IVSEL settings. If the program never enables an interrupt source, the
Interrupt Vectors are not used, and regular program code can be placed at these locations. This
is also the case if the Reset Vector is in the Application section while the Interrupt Vectors are in
the Boot section or vice versa.
10.8
Register Description
10.8.1
STATUS – Status register
• Bit 7 – NMIEX: Non-Maskable Interrupt Executing
This flag is set if a non-maskable interrupt is executing. The flag will be cleared when returning
(RETI) from the interrupt handler.
• Bit 6:3 – Reserved
These bits are unused and reserved for future use. For compatibility with future devices, always
write these bits to zero when this register is written.
• Bit 2 – HILVLEX: High-level Interrupt Executing
This flag is set when a high-level interrupt is executing or when the interrupt handler has been
interrupted by an NMI. The flag will be cleared when returning (RETI) from the interrupt handler.
• Bit 1 – MEDLVLEX: Medium-level Interrupt Executing
This flag is set when a medium-level interrupt is executing or when the interrupt handler has
been interrupted by an interrupt from higher level or an NMI. The flag will be cleared when
returning (RETI) from the interrupt handler.
• Bit 0 – LOLVLEX: Low-level Interrupt Executing
This flag is set when a low-level interrupt is executing or when the interrupt handler has been
interrupted by an interrupt from higher level or an NMI. The flag will be cleared when returning
(RETI) from the interrupt handler.
Table 10-2.
Reset and Interrupt vectors placement
BOOTRST
IVSEL
Reset Address
Interrupt Vectors Start Address
1
0
0x0000
0x0002
1
1
0x0000
Boot Reset A 0x0002
0
0
Boot Reset Address
0x0002
0
1
Boot Reset Address
Boot Reset A 0x0002
Bit
7
6
5
4
3
2
1
0
NMIEX
–
–
–
–
HILVLEX
MEDLVLEX
LOLVLEX
STATUS
Read/Write
R
R
R
R
R
R
R
R
Initial Value
0
0
0
0
0
0
0
0