J-Link Pro to program 3 wire SPI ???

[luudee]

Hi Guys,

I have a J-Link Pro, and am wondering if it can program SPI flashes with DI & DO (MISO & MOSI) tied together ?

The controller requires that we connect the MISO and MOSI together, it has a single SDIO pin, but does in
it's data sheet specify a standard FLASH (W25X05CLS) with 4 pin SPI interface.

I can't find anything in the Segger/J-Link documentation ....

Any pointers appreciated.

Best Regards,
rudi

[ajb]

I doubt it can program them directly, but don't know for sure.  You can use J-Flash to program external memories connected to a supported MCU--it loads a small application into RAM, then it passes data to the application to be written to the memory.  I haven't used that feature and don't know what the limitations are, but might be worth looking at. 

[GromBeestje]

You can connect an SPI flash directly to a J-Link and program it. However, I never heard of SPI flash operation with the DI and DO connected together.

[DavidAlfa]

Most SPI slaves will work fine with SDI/SDO joined together, as SDO is Hi-Z when receiving and SDI is "don't care" when transmitting.
(This should be checked in the datasheet).

But the master must tristate SDO, either manually by disabling the pin, or using SPI 1-pin half-duplex mode, where the same pin does both functions depending if receiving or transmitting.

[luudee]

Just as a follow up:

I talked to tech support at Segger. They say it doesn't directly support it,
but I could use their DPK(?) to create a custom protocol.

Cheers,
rudi