I have a problem with MKV31F51 controller. During debug session it's stucked in secured state. A lot of reprogrammings have been done successfully but after last one "Secured Kinetis device detected" message appeared during device programming. I agrreed with prompt to mass erase device but it not help. I've tried to access device by Segger J-link debugger. AP status register (1) value was read as "0x3E" (mass erase enabled, no reset, secure is enabled), AP command register value was 0x0.
I forced mass erase by writing 0x1 value ("Flash mass erase in progress" bit) to AP command register and value from it was read as 0x1, but i received no ack about erase end, AP reg 1 value is stucked in 0x1. After half an hour a checked again and value was the same.
How can I unlock device?