Atmel XMEGA B, User Manual

Page: 31 / 415

31 XMEGA B [DATASHEET]
8291B–AVR–01/2013
4.15.3 FUSEBYTE2 – Fuse Byte 2

Bit 7 – Reserved
This fuse bit is reserved. For compatibility with future devices, always write this bit to one when this register is written.

Bit 6 – BOOTRST: Boot Loader Section Reset Vector
This fuse can be programmed so the reset vector is pointing to the first address in the boot loader flash section. The
device will then start executing from the boot loader flash section after reset.
Table 4-1. Boot reset fuse.

Bit 5 – TOSCSEL: 32.768kHz Timer Oscillator Pin Selection
This fuse is used to select the pin location for the 32.768kHz timer oscillator (TOSC). This fuse is available only on
devices where XTAL and TOSC pins by default are shared.
Table 4-2. TOSCSEL fuse.
Note: 1. See the device datasheet for alternate TOSC position.

Bit 4:2 – Reserved
These fuse bits are reserved. For compatibility with future devices, always write these bits to one when this register is
written.

Bit 1:0 – BODPD[1:0]: BOD Operation in Power-down Mode
These fuse bits set the BOD operation mode in all sleep modes except idle mode. For details on the BOD and BOD
operation modes, refer to
“Brownout Detection” on page 109 .
Table 4-3. BOD operation modes in sleep modes.
Bit 7 6 5 4 3 2 1 0
+0x02
– BOOTRST TOSCSEL – – – BODPD[1:0]
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value 1 1 1 1 1 1 1 1
BOOTRST Reset address
0 Reset vector = Boot loader reset
1 Reset vector = Application reset (address 0x0000)
TOSCSEL Group configuration Description
0 ALTERNATE
(1)
TOSC1/2 on separate pins
1 XTAL TOSC1/2 shared with XTAL
BODPD[1:0] Description
00 Reserved
01 BOD enabled in sampled mode
10 BOD enabled continuously
11 BOD disabled