FreeCalypso > hg > freecalypso-hwlab
changeset 51:311c800268b8
doc/FTDI-EEPROM-tools: added note about bigger EEPROMs
not providing any more room for strings
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Mon, 22 Apr 2019 23:28:27 +0000 |
| parents | fc6f64fb5714 |
| children | ace3ed1d5ddf |
| files | doc/FTDI-EEPROM-tools |
| diffstat | 1 files changed, 10 insertions(+), 0 deletions(-) [+] |
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--- a/doc/FTDI-EEPROM-tools Mon Apr 22 23:20:13 2019 +0000 +++ b/doc/FTDI-EEPROM-tools Mon Apr 22 23:28:27 2019 +0000 @@ -194,6 +194,16 @@ 93C66 EEPROMs and I don't plan on acquiring or building any, hence this minimal 93C66 support is completely untested - use at your own risk. +It also needs to be noted that with our current RE-based understanding of FTDI's +undocumented EEPROM structure, using a bigger EEPROM does NOT provide more room +for strings: all that happens with -b and -B options is that a gap of 64 unused +EEPROM words is inserted between the end of the fixed structure and the +beginning of strings. The exact same arrangement has been observed in all 93C56 +EEPROM images found in the wild, presumably produced with FTDI's official tools, +including FTDI's own USB-COM232-PLUS2 board - thus it is not clear at all if +FT2232x chips actually support longer strings with bigger EEPROMs, and if not, +what does one need a bigger EEPROM for... + For the format of config files read by our ftee-gen2232[ch] tools and what settings can be tweaked, read the source code.