IWR6843AOP: SPI Chip Select

David Wiegand

Part Number: IWR6843AOP

Hello,

in the data sheet of the IWR6843AOP (SWRS237A, p. 46) it is said that the chip select pin of the SPI should be toggled for every 16 bits.

In the reference manual (SWRU522E) of this chip there is nothing to read about it and in a test program I got it working without toggling the pin (SPI clock frequency 10 MHz, 5-Pin operation).
Is there a technical background why toggling should be done or can I rely on the reference manual that toggling is not required?

Best regards,
David

over 4 years ago

0 Akash Gondalia over 4 years ago

TI__Guru 50240 points

Hi David

Which test program are you referring to? Is it on either ti.com or dev.ti.com?

Regards,

0 David Wiegand over 4 years ago in reply to Akash Gondalia

Prodigy 30 points

My implementation is based on an out of box demo program, where i added a spi slave. My configuration of the slave is the following:

params.mode = SPI_SLAVE;
params.dataSize = 8U;
params.u.masterParams.bitRate = (uint32_t) 10e6;
params.frameFormat = SPI_POL1_PHA0;
params.shiftFormat = SPI_MSB_FIRST;
params.pinMode = SPI_PINMODE_4PIN_CS;
params.csHold = 1;
params.dmaEnable = 0U;

I followed the example program from SDK/drivers for spi implementation but adjusted the settings a bit because I don't want to toggle the chip select (my master doesn't support this kind of chip select toggling).

Best regards,
David

0 Akash Gondalia over 4 years ago in reply to David Wiegand

TI__Guru 50240 points

Hi David

I'll need a couple more days to look into this.

Regards,

0 David Wiegand over 4 years ago in reply to Akash Gondalia

Prodigy 30 points

Hello Akash,

Were you able to find out?

Best regards,
David

0 Akash Gondalia over 4 years ago in reply to David Wiegand

TI__Guru 50240 points

Hi David

I can confirm toggling of CS is not needed and there is no known issue from not doing so.

Regards,

Sensors

Sensors forum

IWR6843AOP: SPI Chip Select