Tooltron

We need to use the Self-Programming Flash feature of the ATTIny2313. Page 155 of the datasheet.

Notes from the datasheet:

• Need to make sure the SELFPRGEN fuse is set
• Write to the flash 1 page at a time
  1. Fill temp page buffer
  2. Erase the page to write (Page Erase)
  3. Write the buffer to the page (Page Write)

• Erasing a page
  1. Set page address in the Z-pointer (ZH + ZL, Z[15:0])
  2. Write 0x03 to SPMCSR and immediately execute SPM ASM instruction

• Writing a temp page
  1. Set up address in Z-pointer
  2. Put data in R1:R0
  3. Write 0x01 to SPMCSR and execute SPM ASM instruction
• Do not do any EEPROM writes as it will erase the temp page

• Writing a page
  1. Set up the page address in Z-pointer
  2. Write 0x5 in SPMCSR and execute SPM ASM instruction
• Must be page aligned address
• Will pull the data from the temp buffer
  Notes about setting fuses:

This page describes how to set/read the fuses through AVRDUDE pretty clearly. We have to convert them to hex ourselves.

http://electrons.psychogenic.com/modules/arms/art/14/AVRFusesHOWTOGuide.php

Note that the self-program enable fuse is located in the efuse section, not fuseh or fusel as all the standard fuses.

AVR-LIBC seems to have some macros to make this easier: http://www.nongnu.org/avr-libc/user-manual/group__avr__boot.html

512byte boot loader. We can probably modify this. It's setup to use the uart protocol I believe. Need to login to avrfreaks to see it though.

http://www.avrfreaks.net/index.php?module=Freaks%20Academy&func=viewItem&item_type=project&item_id=625