STM32 JTAG question.

Posted on May 17, 2011 at 14:32

Thank you

for your reply

but

I

need to

completely

disable

JTAG

.

The

main

funkcjii

not

blocking

connects

after

a reboot

.

someone knows

other

solution

?

.

Posted on May 17, 2011 at 14:32

You'd want to do it as early as possible. If in C you'd want to put it up at the beginning of main(), a better place would be in assembler at the reset entry point (startup.c, or whatever). This would reduce the window to break it. Add your own trap door code to allow you to re-enable later if required.

To be effective you'd really want to bury the JTAG contacts under the BGA to limit physical contacts (ie provide not JTAG connector at all), still someone could remove the part from the PCB.

To be honest I think you're wasting your time, the people who break into these things are better skilled and equipped, and understand the part better.

Posted on May 17, 2011 at 14:33

Thank you

for your reply

but

I

need to

completely

disable

JTAG

.

 

Yeah, well good luck with that.

Posted on May 17, 2011 at 14:33

''someone knows

other

solution

?''

 

Solution to what, exactly?

You have presented your idea of a ''solution'' (disabling JTAG), but you haven't said what problem you are actaully trying to solve!

You haven't said what you are actually trying to achieve  by this.

Without knowing what you are actually trying to achieve,  it is impossible to know what might be appropriate suggestions to make!

When I am out showing off PSoC I will have customers draw out a schematic and ask if PSoC can do that.

A schematic is a solution, not a definition

. I end up asking just what are they trying to do. When they tell us We then figure out how to do it the PSoC way.

 

 

See:

http://www.cypress.com/?rID=50113

- last paragraph

 

You are effectively showing us a schematic, rather than explaining the problem that you are trying to solve.