CC2640R2F: SPI data direction?

Markel Robregado

Part Number: CC2640R2F

Hi,

I am trying to port SPI initialization from NXP KW38 to CC2640R2F. At NXP KW38 they are able to set the data shift direction to MSB first.

gMasterConfig.ctarConfig.direction = kDSPI_MsbFirst;

At CC2640R2F there is no option to set the data shift direction. What is the default data shift direction for CC2640R2F SPI?

-kel

over 1 year ago

0 Marie H over 1 year ago

TI__Guru 73361 points

Hi Markel,

Which version of the SImpleLink SDK are you using?

Cheers,

Marie H

0 Markel Robregado over 1 year ago in reply to Marie H

Guru 85655 points

Hi Marie H,

I am using tirtos spimaster example program from SDKv5.30. Another thing is the SPI CS automatically goes low when there is SPI transmission. But, what if the SPI slave enable is active high.

-kel

+1 Fausto C over 1 year ago in reply to Markel Robregado

TI__Intellectual 2115 points

Hi Markel Robregado,

Looking at the information in the TRM in chapter 20.4.4, it seems that the shift direction is always MSB first, no matter the frame format you are using. Looking at the SPI driver I can also confirm that this cannot be configured.

Regarding the CS pin, the SPI module will automatically pull down the CS pin when using the 4-wire configuration. This behavior cannot be changed in the SPI HW, therefore if your use case require CS active high, you will have to use the SPI driver in 3-wire configuration (assign spiCC26XXDMAHWAttrs[CC2640R2_LAUNCHXL_SPI<X>].csnPin = PIN_UNASSIGNED) and toggle the CS pin manually using a GPIO.

Best regards,

Fausto C

0 Markel Robregado over 1 year ago in reply to Fausto C

Guru 85655 points

Thanks.

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CC2640R2F: SPI data direction?