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MSP430FR57xx and blown security fuse

Other Parts Discussed in Thread: MSP430FR5736, MSP-TS430PW28

I was programming and debugging code on a MSP430FR5736 over the past few days and then this morning started again and found that I got the message that security fuse flown or device not recognised. In the log it said security fuse blown. I have looked back through previous post but could find nothing that helped. I am using MSP-430UIF and IAR assembler. I have a MSP-TS430PW28 board and then my target board. I do not have an external power supply. I have check continuity between the TS430PW28 and the MCU and all is fine. I am using SBW to program. I erase main memory only, but have also treid erasing info memory as well. I have tried a number of boards. It seems they program the first time but not the second. It is as though I am blowing the fuse, or creating a condition that simulates this. I have 3.28V on Vcc. I have no shorts between any of the 4 pins. I have a pull up resistor for RST. 

Any suggestions would be appreciated as I do not want to blow up any more.

Thanks

Peter

  • This situation can be fixed by erasing all the FRAM memory. You can use BSL to do that. (If you do not have the interface required for BSL, there may be other methods too.)

    FR5736 dose not have a real "security fuse". A "virtual fuse" is implemented by the contents of 4 bytes of FRAM near the high address end just before the interrupt vectors.

  • Hi OCY

    I did read up on the 2 locations for signature 1 & 2. I have access to the RXD/TXD pins of the chip but have no BSL facilities. I have never used this but suspect I should "get involved" so I am prepared in future. Any suggestions? I also had some feedback saying that IAR 5.5 was a problem for that person and all OK when he moved back to IAR 5.3.

    Thanks

    Peter

  • The real danger is that there are 2 more locations that can lockup BSL. When both JTAG and BSL are locked up, I do not know if there is any way out.

    I have not looked into this situation for years(?) now. Hope someone else can be more helpful.

  • PeterG said:

    I did read up on the 2 locations for signature 1 & 2. I have access to the RXD/TXD pins of the chip but have no BSL facilities. I have never used this but suspect I should "get involved" so I am prepared in future. Any suggestions?

    AFAIK, you can't unblow soft fuse (if it is blown) on MSP430x5xx without BSL. For BSL hardware can be used MSP430G2 LP (slaa535 LaunchPad-Based MSP430 UART BSL Interface). (Un)blowing FRAM soft fuse is explained here...

    http://forum.43oh.com/topic/2972-sbw-msp430f550x-based-programmer/?p=43889

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