Using the integrated ezFET to program MSP430 on custom pcb.

P Vermeulen

Other Parts Discussed in Thread: MSP430FR5739

Hello.

I have a couple of MSP430fr5739 experimenter boards with integrated ezFET for programming and debugging. i am about to design a custom pcb with the same MCU on it, but would like to use the same programming capabillities via ezFET without adding this to my board. Would it be possible to connect the ezFET from the experimenter oard via the jumper pins to my custom board and make use of the same programming features the experimenter board has?

The underlying question is: If I purchase a MSP430fr5739 MCU without the experimenter board, does it have the Boot Strap Loader enabled by default?

Thanks in advance for your reply.

over 10 years ago

0 Dennis Eichmann over 10 years ago

Guru 74080 points

Yes you can use the eZ-FET for programming external MCUs. Disconnect the TEST and RST jumpers and wire them to your external processor. But care has to be taken with the voltages. The eZ-FET drives out at 3.6V, so your target MCU should a) be powered by the LaunchPad or b) have a similar supply voltage. If the supply voltage is less than that, you can add series resistors for protection. A common GND is mandatory, of course.

0 P Vermeulen over 10 years ago in reply to Dennis Eichmann

Prodigy 50 points

Thanks for the reply.

Are the RST and TEST pins the only pins that need to be reconnected? What about the other pins: The RxD and TxD?

So you are sure when I order this MSP430fr5739 processor it comes preloaded with a BSL that is used for this ezFET connection?

Thanks in advance.

0 Dennis Eichmann over 10 years ago in reply to P Vermeulen

Guru 74080 points

It is RST, TEST, GND (and Vcc).

Look at this document, chapter 2 - it lists the device compatibilities.

Dennis

0 P Vermeulen over 10 years ago in reply to Dennis Eichmann

Prodigy 50 points

Hi Dennis,

After reading the document I can conclude that my previous assumption (spy by wire uses BSL) was wrong.

The MSP430FR5739 supports 2 wire JTAG (SBW), no BSL support. I will do some tests to see if I can get it to work.

Thanks for your help.

0 Dennis Eichmann over 10 years ago in reply to P Vermeulen

Guru 74080 points

Sorry, I missed that. Yes, the eZ-FET (lite) uses 2-wire (RST/TEST) SBW.

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Using the integrated ezFET to program MSP430 on custom pcb.