Atmel AT32UC3A3128, Manual

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32072H–AVR32–10/2012
AT32UC3A3
35.2.2.1 Security measure and control location
A security measure is a mechanism to either block or allow SAB access to a certain address or
address range. A security measure is enabled or disabled by one or several control signals. This
is called the control location for the security measure.
These security measures can be used to prevent an end user from reading out the code pro-
grammed in the flash, for instance.
Below follows a more in depth description of what locations are accessible when the security
measures are active.
Table 35-2. SAB Security measures.
Security measure Control Location Description
Security bit
FLASHC security
bit set
Programming and debugging not possible, very restricted
access.
User code
programming
FLASHC UPROT
+ security bit set
Restricts all access except parts of the flash and the flash
controller for programming user code. Debugging is not
possible unless an OS running from the secure part of the
flash supports it.
Table 35-3. Security bit SAB restrictions
Name Address start Address end Access
OCD DCCPU,
OCD DCEMU,
OCD DCSR
0x100000110 0x100000118 Read/Write
User page 0x580800000 0x581000000 Read
Other accesses - - Blocked
Table 35-4. User code programming SAB restrictions
Name Address start Address end Access
OCD DCCPU,
OCD DCEMU,
OCD DCSR
0x100000110 0x100000118 Read/Write
User page 0x580800000 0x581000000 Read
FLASHC PB
interface
0x5FFFE0000 0x5FFFE0400 Read/Write
FLASH pages
outside
BOOTPROT
0x580
BOOTPROT size
0x580 Flash size Read/Write
Other accesses - - Blocked