Programming problem with a P&E Multilink Universal and K40 in CW10.X

[greglapin]

I've had a problem programming with a Multilink Universal connected to a K40 processor.

Using CW10.4 (and later CW10.6) I have 14 identical boards that all programmed and debugged properly.

Over time 4 of the boards would no longer open in the debugger.

I discovered that I could program those board with the Flash Programmer utility in CW10.X.

However, during the Flash write there was no Verify on those boards. The other boards performed a Verify stage after each Program stage.

I'm not sure what changed for those 4 boards but they appear to have lost the ability to read from the JTAG port.

Is there some kind of security bit in the K40 that might have been set inadvertently?

[Hui_Ma]

Hello Greg,

Flash configuration filed byte address 0x40C is Flash security byte, which will be loaded into FTFL_FSEC register after chip reset.

The Flash block mass erase of 0x40C will be erased to value 0xFF, which will cause K40 chip in secured mode and external JTAG communication will be blocked. An external mass erase will unlock that chip.

When customer debug with secured K40 board, the CW will popup window ask for if it need mass erase to unlock the chip.

Customer can unlock it by press "Yes" option with P&E Multilink Universal tool.

Wish it help.

best regards,
Ma Hui

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