There was a discussion about the security fuses and some enhancements of
the BSL password protection on the MSP430 day 2008 in berlin. I only
remember some basic infos:
- you can only blow the JTAG security fuse once because it's a physical
fuse. so there's no way to reset these fuses.
- the BSL password is stored at a memory address just before the
interrupt vector table (take a look at the device specific datasheets
because the location depends on 32/64 byte vector table size)
- AFAIR there is some brute force password cracking protection in
msp430f2xxx devices
- there is a way to reset the BSL password, but this also deletes the
complete flash contents (don't ask me how to do it)
gunther
Chris Liechti schrieb:
Grant Edwards schrieb:
On 2008-06-26, Chris Liechti <[email protected]> wrote:
burning the fuse required >7V that the adapter must provide.
Further, it looks like the TI USB FET won't work.
i though it should? "msp430-jtag -l TIUSB --secure" might
work.
Once blown, can the chip (and fuse) be erased via JTAG or
firmware?
the BSL isn't influenced by the security fuse.
the fuse can't be "repaired", thus the JTAG is permanently
disabled.
So it really _is_ a "fuse". That's in contrast to Atmel's AVR
where they call EEPROM cells "fuses". Presumably there's some
historical reason for Atmel's use of that term, but it sort of
makes them sound dumb when they talk about "un-blowing" a fuse.
i don't know how it is technically implemented. but the specs for
"burning" require a higher voltage and some current. that seems to be
enough power to melt a metal layer wire. but EEPROMs also require higher
voltages...
it is certainly not in the normal flash area as that controller has a
charge pump.
chris
-------------------------------------------------------------------------
Check out the new SourceForge.net Marketplace.
It's the best place to buy or sell services for
just about anything Open Source.
http://sourceforge.net/services/buy/index.php
_______________________________________________
Mspgcc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/mspgcc-users
