Generic function enabling external programming on TPI devices. This
function sets the required guard time (which is passed in as parameter),
checks the TPI identification register, writes SKEY command + SKEY, and
finally polls the NVMEN bit in TPISR.
avr.h: Add prototype definitions of avr_tpi_program_enable() and
avr_tpi_chip_erase().
avrftdi_tpi.c: Removes tpi_skey_cmd array, containing the SKEY command
and the SKEY bytes.
tpi.h: Adds tpi_skey_cmd array, containing the SKEY command and the SKEY
bytes, but in the reverse order of tpi_skey.
git-svn-id: svn://svn.savannah.nongnu.org/avrdude/trunk/avrdude@1167 81a1dc3b-b13d-400b-aceb-764788c761c2
Hannes Weisbach
Joerg Wunsch