K64 has my Bootloader installed.
It has an Application that loads at 0x1000.
Two boards - same issue.
Both boards were working fine for a week. My tester (in Canada) was helping debug the application and cycled power to the micro. Power had NOT go all the way to zero before it came back on. Same situation - both boards - different days. After this power cycle event -- the App fails to run -- I think a Hardfault is occurring.
The Bootloader performs a checksum which passes but when it jumps to the App -- it just dies. I have an LED that is suppose to light when a HardFault occurs and it's lit.
I wrote a remote loader that would talk to the Bootloader and update the Application. Process tested on my bench works perfectly.
On the two subject boards - the new Application is made available to the Bootloader. It flashes the new App into the K64 - and verifies each block that is flashed -- also verifies overall checksum. All pass - but fails when it jumps to the App.
I can not think of a failure mode associated with power cycling that would do something to the micro.
Do You have any ideas or comments?
I suspect the failure is NOT flash related since It just performed a reflash and verified itself.
Can anyone think of a component within the micro that can be suspect?
Any ideas or comments are welcomed -- this one has me puzzled!!.
By the way ... I've the the flash protected so I can't connect a jtag debugger to see what's going on -- got to think this one thru.