Other Parts Discussed in Thread: UNIFLASH,
Hi,
Our product uses MSP430F6779A processor. We want to know the easiest process possible by which we can blow the reversible "electronic fuse" in this device, so that the JTAG connector is secured in field so no one can steal the device and extract our code using JTAG. In the event of unit failure in the field, we would then want to reverse the "electronic fuse" back in-house should the unit need to be returned from the field for analysis. There are many different TI Tools ("Flasher.exe, Uniflash, BSL Scripter, CCS interface) that went through different revisions which included (and still do include) this functionality of a disabling the JTAG. Series F5xx and F6xx mention "electronic fuse" which is what we thing we want. Some documents say this can be done "only once" others don't say at all. The addresses of the password and length of password are different for different devices.
We see a note saying the 8-byte password is at 0x17F8 - 0x17FF, and anything other than 0000 | 0000 or FFFF | FFFF written to this address range will lock the JTAG. But it's not clear how to actually accomplish this with the tools.
To be clear, we DON'T NEED general conversation. We need a specific set of steps for F6779A to allow us to disable JTAG, and then at a later time reenable JTAG, in a way that will prevent extraction of source code from Flash memory.
We have spent several days experimenting with this and have succeeded in killing one F6779A CPU by using flasher.exe with option -f, so now are asking for help. We need to stop guessing how the security system with JTAG works and get a clear understanding.
Sincerely,
Kip Leitner