User Manual

MPR/MIB User’s Manual
Wireless Sensor Networks
Doc. # 7430-0021-06 Rev. A Page 33
10 ATMEGA128 FUSES
The ATMega128L processor on the Motes has many programmable fuses to control various
parameters. Refer to Atmel’s technical information for the ATMega128L for a complete
discussion of the fuses (http://www.atmel.com/dyn/resources/prod_documents/2467s.pdf). There
are two fuses that TinyOS users should be aware of as setting these fuses incorrectly will cause
the unit to not operate correctly.
10.1.1 Atmega103 compatibility mode fuse
This fuse put the ATMega128 in the ATMega103 compatible mode. This fuse was set for the
older generation MICA units. It must be disabled for MICA2 and MICA2DOTs.
10.1.2 JTAG fuse
This fuse enables users to use the Atmel JTAG pod for in-circuit code debugging. Units are
shipped with JTAG enabled. As discussed in the previous section on battery voltage monitoring,
if JTAG is enabled, it will cause inaccurate measurements on ADC channel 7.
10.1.3 Using UISP to set fuses
The UISP utility used to download code to the MICAz, MICA2, or MICA2DOT on a
programming board can also be used to set and unset fuses of the Atmel
®
ATMega128.
Table 10-1. UISP Commands for Setting the ATMega128’s Fuses.
Action Command
Disable JTAG fuse uisp -dprog=<programmer> --wr_fuse_h=0xD9
Enable JTAG fuse uisp -dprog=<programmer> --wr_fuse_h=0x19
Enable native 128 mode uisp -dprog=<programmer> --wr_fuse_e=ff
<programmer> is the device you are using to interface to the Mote from a computer. The current options
are dapa (for an MIB500), mib510 for a MIB510; and EPRB for a MIB600.
Users can also edit the file called profile in the cygwin/etc/ directory and enter an alias. One
example is this alias to disable the JTAG fuse:
alias fuse_dis="uisp -dprog=<programmer> --wr_fuse_h=0xD9"
Therefore, when fuse_dis and is entered into a Cygwin command line, the script will be
executed.