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MSP430F133: JTAG FLASH ISSUE - FUSE BLOWN STATUS

Part Number: MSP430F133

Since a long time, we have some issues with the programming of the MSP430F133.

The programming is done with the JTAG port - TCK, TMS, TDI, TDO, RST, Vcc, GND. The MCU is programmed at the beginning of the test sequence with a test software

At the end of the test sequence, the application software is loaded and the offset data are written @1080

 The issue is following,  randomly, we get the error message "JTAG FUSE BLOWN" -> after this message , the processor is not writeable anymore

 The flasher device is a FLASH Pro 430  Elprotronic , the processor is a MSP430F133.The flasher is isolated with relays (between flasher and acces point)

The wire length total is less than 40cm. The DUT is powered from the flasher during the programming (3.3V)

The programming is done using the MSP430FPA1.dll (from Elprotronic)

The devices under test are "power supply board" with different configuration but always with the same daughter board (where the MSP430 is located)

The DUT is tested in version 75W, 150W, 300W, 600W in range 12V, 24V, 48V

The first programming (with a fresh board or a board not powered since a long time) is always pass

Then the test process switch the main power ON and OFF many times during the test.

At the end of the test, the main power is disconnected from the DUT, then the programming relays are switch ON

 If the programming is launch immediatly (or with a small delay..ie 5s) then the programming is failed with the message "FUSE BLOWN"

 So the question is :

What could generate the fuse blown state during the programming

We monitor the 3V3 during the programming (with oscilloscope) and we don't see any transient phenomenon (ok we don't have a high performance scope), it stays stable at 3V3

For sure we do not see voltage over the 3.6V, we check the grounding also

 If we wait more than 30..50s, then the programming is OK and we can restart the test process.

What should we check and monitor to have an idea about the destruction of the JTAG during the programming

 The only way to avoid the fuse blown, is to wait a long time (at least more than 30s..60s), behaviour looks like a cap discharge but we also did a discharge of the primary capacitor (charge at 400 V)

and the secondary capacitor

  • Hi Denis,

    Interesting.  Let me make sure I have this correct.

    You are not explicitly blowing the JTAG fuse as part of the programming sequence, but you see this error from the Elprotronics programmer after the initial programming followed by several power cycles, then wait a short time (5sec) to attempt to re-program.  If you perform same sequence but wait longer, (60sec) you can reprogram the device without this error, correct?

    Can you measure the MSP430 VDD 5 seconds after you perform the multiple power cycles,  then measure again after 60 seconds and tell me what you measure?

  • Hi Dennis,

    You got it, exactly what we are doing in the process. I will ask the factory to make the measurement, do we need a specific accuracy for that measurement or a standard voltmeter is enough ?

  • A standard 3-1/2 digit voltmeter is fine.  What I'm guessing is happening is, after the 5 sec delay the voltage on the device is in a region monitored by the SVS (supply voltage supervisor) and is keeping the device in reset during the time the JTAG programmer is attempting to program the device.  If delay is short, the voltage doesn't drop below the POR(min), which according to the datasheet can be 1.4v down to 0.8v, depending on temperature.

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