Atmel AT32UC3C0128C, Manual

Page: 7 / 37

7
32166A–AVR32806–06/11
Atmel AVR32806
See
Section 6.2.2.2
for the default preprogrammed value of this configuration word.
Table 6-1. Boot loader flash user page Configuration Word1.
Config
Word1 @
808001FCh
Name Description
7:0 ISP_CRC8_1 CRC8 of the boot loader Configuration Word1
usingthe polynomial:
P(X) = X
8
+X
2
+X+1.
This CRC is used to check the validity of
Configuration Word1.
8 ISP_IO_COND_EN When at 1, tells the boot process to use the user
page Configuration Word2 to determine the I/O
conditions to test to know whetherto start the USB
DFU ISP or the application. Refer to
Table 6-2
for a
description of the user page Configuration Word2.
Setting this bit to 0 allows the application to save a
GPIO pin and to free the penultimate word of the
user page, but the ISP will then be unreachable until
the ISP_FORCE bit is set to 1. This behavior can be
useful when extending the Atmel default boot loader
with an applicative boot loader (see
Section 7.6.3.3
).
9 ISP_FORCE When at 1, tells the boot process to start the USB
DFU ISP process without testing any other
conditions.
15:10 Reserved Reserved. Set to 3Fh.
31:16 ISP_BOOT_KEY_1 Boot key=E11Eh. This key is used to identify this
word as meaningful for the boot loader.