3.10.12.2 Fuse Low Byte

Table 3-112. Fuse Low Byte

Bit No

Lock Bit Byte

Description

Default Value

7

CKDIV8

Start-up with system clock divided by 8

1 (unprogrammed)

6

DWEN (2)

DebugWIRE enable

1 (unprogrammed)

5

SPIEN (3)

SPI Enable

0 (programmed)

4

WDTON

Watchdog timer always on

1 (unprogrammed)

3

EESAVE

Keep EEPROM contents during chip erase

1 (unprogrammed)

2

BOOTRST

Select reset vector location:

1: Reset vector is located at 0x0000 (ROM)

0: Reset vector is located at 0x4000 (user Flash/user ROM)

1 (unprogrammed)

1

RSTDISBL(1)

External reset disable

1 (unprogrammed)

0

EXTCLKEN

External clock enable

1 (unprogrammed)

Note:
  1. After programming the RSTDISBL fuse, HVSP must be used to change fuses and allow further programming.
  2. DWEN fuse must be unprogrammed when lock bit security is required (see Program and Data Memory Lock Bits).
  3. The SPIEN fuse is not accessible in ISP mode.