
32
32000D–04/2011
AVR32
When trying to access secure world memories from the nonsecure world, a bus error
exception will be raised, and the access will be aborted. Writes to secure system registers
from within the nonsecure world will simply be disregarded without any error indication.
The On-Chip Debug (OCD) system is modified to prevent any leak of proprietary code or
data to the nonsecure world. This prevents hacking through the use of the OCD system.
4.2
Secure state programming model
The programming model in the secure state is similar to in normal RISC state, except that
SP_SEC has been banked in, and the secure system registers are available in all privileged
modes.
Figure 4-1.
Register File in AVR32A with secure context
Application
Bit 0
Supervisor
Bit 31
PC
SR
INT0PC
FINTPC
INT1PC
SMPC
R7
R5
R6
R4
R3
R1
R2
R0
Bit 0
Bit 31
PC
SR
R12
INT0PC
FINTPC
INT1PC
SMPC
R7
R5
R6
R4
R11
R9
R10
R8
R3
R1
R2
R0
INT0
SP_APP
SP_SYS
R12
R11
R9
R10
R8
Exception
NMI
INT1
INT2
INT3
LR
Bit 0
Bit 31
PC
SR
R12
INT0PC
FINTPC
INT1PC
SMPC
R7
R5
R6
R4
R11
R9
R10
R8
R3
R1
R2
R0
SP_SYS
LR
Bit 0
Bit 31
PC
SR
R12
INT0PC
FINTPC
INT1PC
SMPC
R7
R5
R6
R4
R11
R9
R10
R8
R3
R1
R2
R0
SP_SYS
LR
Bit 0
Bit 31
PC
SR
R12
INT0PC
FINTPC
INT1PC
SMPC
R7
R5
R6
R4
R11
R9
R10
R8
R3
R1
R2
R0
SP_SYS
LR
Bit 0
Bit 31
PC
SR
R12
INT0PC
FINTPC
INT1PC
SMPC
R7
R5
R6
R4
R11
R9
R10
R8
R3
R1
R2
R0
SP_SYS
LR
Bit 0
Bit 31
PC
SR
R12
INT0PC
FINTPC
INT1PC
SMPC
R7
R5
R6
R4
R11
R9
R10
R8
R3
R1
R2
R0
SP_SYS
LR
Bit 0
Bit 31
PC
SR
R12
INT0PC
FINTPC
INT1PC
SMPC
R7
R5
R6
R4
R11
R9
R10
R8
R3
R1
R2
R0
SP_SYS
LR
Secure
Bit 0
Bit 31
PC
SR
R12
INT0PC
FINTPC
INT1PC
SMPC
R7
R5
R6
R4
R11
R9
R10
R8
R3
R1
R2
R0
SP_SEC
LR
SS_STATUS
SS_ADRF
SS_ADRR
SS_ADR0
SS_ADR1
SS_SP_SYS
SS_SP_APP
SS_RAR
SS_RSR