CCS: DRV8301 SPI Communication, MISO is not working.

I find out the following: 

This is the DVDD Pin. according to the datasheet, DVDD pin should be output 3.3V.

but the signal is not stable and so strange.

This pin is the AVDD. I think this pin should be output 6V. but this pin is also strange.

You might take a look at the link below that has reference hardware design files and implementation codes for DRV8301.

https://www.ti.com/tool/BOOSTXL-DRV8301

The following code is for your reference if you are using the driverlib based configuration.

// Must put SPI into reset before configuring it
SPI_disableModule(obj->spiHandle);

// SPI configuration. Use a 500kHz SPICLK and 16-bit word size, 25MHz LSPCLK
SPI_setConfig(obj->spiHandle, DEVICE_LSPCLK_FREQ, SPI_PROT_POL0PHA0,
SPI_MODE_MASTER, 400000, 16);

SPI_disableLoopback(obj->spiHandle);

SPI_setEmulationMode(obj->spiHandle, SPI_EMULATION_FREE_RUN);

SPI_enableFIFO(obj->spiHandle);
SPI_setTxFifoTransmitDelay(obj->spiHandle, 0x10);

SPI_clearInterruptStatus(obj->spiHandle, SPI_INT_TXFF);

// Configuration complete. Enable the module.
SPI_enableModule(obj->spiHandle);

Hi Yanming Luo

thanks for your reply. 

I have questions

as you seen my reply about DVDD AVDD, is that right? 

DVDD voltage are look like sine wave and Vrms is almost 3.714v. is that right?

Thank you for your reply.

-Garam Park

we've tried to your code, but still miso is not working.

- Garam Park-

You might take a look at the reference schematic and the datasheet of the DRV8301, make sure the DRV8301 works well first. I forward your thread to the expert of the DRV device. 

Hello Garam,

Yes, these waveforms for AVDD and DVDD are the root cause. Unfortunately, these are generated internally so there's not a whole lot to check. Most of the time, its because of:

1. Assembly issues
   1. Specifically with bad pin contact and the power pad not making good contact
2. Bad layout
   1. Specifically, the GND for the pins are long, skinny, or jump through a lot of vias and capacitors are far away from the pin
3. Incorrect capacitor values, or ones that have been derated

That is in order of likelihood.

Assembly Issues:

This one is very tough to prove and mostly systematic to check. I would recommend:

• Replace the DRV8301 and seeing if the issue disappears
• Using a known good board, and swapping the device to a known good board to see if the issue follows the part. Then swapping the device back to the original board to see if assembly was the issue (assuming it works well on the 2nd board). This is known as an ABA swap
• Comparing the waveforms to an EVM (as I assume you're using your own board) and checking your FW on the EVM

Once you have tried some of these, we can review your layout and see if we can make some improvements.

Best,

-Cole