Datasheet

278
32117D–AVR-01/12
AT32UC3C
15.9.3 Fuses in User Page (address 0x80800000)
15.9.3.1 First word (address 0x80800000)
• SS_ADRR: Size of the CPU RAM controlled by the Secure State
The section of the CPU RAM controlled by the Secure State is from address 0x00000000 to address (SS_ADRR << 10).
• SS_ADRF: Size of the Flash controlled by the Secure State
The section of the Flash controlled by the Secure State is from address 0x80000000 to address (SS_ADRF << 10).
• WDTDISRV: WatchDog Timer auto disable at startup
0: The WDT is automatically enabled at startup, the WDTAUTO fuse of the WDT is set.
1: The WDT is not automatically enabled at startup, the WDTAUTO fuse of the watchdog timer is not set.
Please refer to the WDT chapter for detail about time-out settings when the WDT is automatically enabled.
The devices are shipped with the User page erased (all bits 1).
15.9.4 Bootloader Configuration
The USB/USART bootloader uses two words in the flash user page to store its configuration:
• Configuration word 1 at address 0x808001FC is read first at boot time to know if it should
start the ISP process unconditionally and whether it should use the configuration word 2
where further configuration is stored.
• Configuration word 2 at address 0x808001F8 stores the I/O conditions that determine which
of the USB DFU ISP and the application to start at the end of the boot process.
Please refer to the bootloader documentation for more information.
Table 15-13. User Page Fuse Description
31 30 29 28 27 26 25 24
WDTDISRV SS_ADRR[14:8]
23 22 21 20 19 18 17 16
SS_ADRR[7:0]
15 14 13 12 11 10 9 8
SS_ADRF[15:8]
76543210
SS_ADRF[7:0]