Datasheet

PROGRAMMING THE TARGET SYSTEM
3) Install and Run the Handheld Programmer software
• Select the AVR device you want to use on the device screen
• The next screen allows you to select whether the Fuses (not Lockbits which will
always appear) should be programmed. Check the Fuse Enable box to program
fuses.
Notes:
• The whole AVR is erased (Flash and EEPROM) when a Flash file is selected
• To preserve the EEPROM data, the EESAVE fuse must be enabled. This fuse
prevents the EEPROM from being erased. Do not select an EEPROM file if
you want to keep EEPROM data
• To program EEPROM only, select an EEPROM file but no Flash file. This will
NOT work if device is locked.
Note: The EEPROM is not fully erased, so if your new data is smaller than
the existing data in the EEPROM, some of the old data will be left. To avoid
this happening, see Skip FF in EEPROM section
• Fuses can be programmed before erase – see below. This means you can set
the EESAVE fuse to preserve EEPROM data if it is not already set. Again this
will not work if device is locked.
• The next screens are Lockbits followed by Fuses (if Fuse Enable is checked).
Notes:
DWEN (Debugwire Enable) and RSTDISBL (Reset Disable) Fuses are
omitted because setting either of these fuses disables further serial
programming of the AVR. Contact support if you need to set these fuses.
• The screen after Fuses screen is for Startup Time and Bootblock settings.
• The next screen is for setting the target voltage.
Notes:
This setting will change depending on whether the target is powered or not. See
section below on Power Options. As a general rule:
1) If Programmer powers target, set voltage to required target voltage
2) If target is powered and Vcc is connected to ISP header, set voltage to 0V
3) If target is powered and Vcc is NOT connected to ISP header, set voltage to
match target voltage – Vcc
• The next screen is more programmer settings
Notes:
• Speed Settings: The programmer should work on Fastest setting unless you
have a very slow clock (<1MHz) or you have capacitors on programming
lines. If you get programming errors when using the programmer, try a slower
setting.
• Check Program fuses before erase if you want to alter behaviour, e.g. set
EESAVE fuse.