Re: [avrdude-dev] Patch for fuse and lock-bits with avr910

[Theodore A. Roth]

On Fri, 16 May 2003, Jan-Hinnerk Reichert wrote:

:)Hi all,
:)
:)I have written a patch that allows to read and write fuse bits with an avr910 
:)programmer (at least if it supports the "New Universal Command").
:)
:)Should work with avr910 version 2.2 and newer (don't have access to older 
:)firmware.
:)
:)Patch is against latest CVS version of "avr910.c"
:)
:)This is how it works:
:)1) It implements "avr910_cmd()": sending arbitrary SPI-commands
:)2) avr910_read_byte() and avr910_write_byte() call avr_read_byte_default(), 
:)resp. avr_write_byte_default(), if memtype is neither flash nor eeprom.

I've been reviewing and testing your patch. One question though.

Can you explain the reasoning behind the "last_spi_byte" variable in the
avr910_cmd() function?

It doesn't seem to have any obvious purpose to me.

One onther item: firmware versions < 2.0 don't have the '.' command 
(universal command) and will thus fail. I'm thinking that this case should 
be caught and avr910_cmd() should return -1.

Ted Roth