Linux/LAUNCHCC3220MODASF: Bit Rate SPI 20Mbit

Hi Jan
should the SPI baudrate be 20 Mbit with 20 MHz clock?
Thanks
Nguyen

Hi Nguyen,

electronics.stackexchange.com/.../spi-communication-bits-per-second-vs-hz

Jan

Thanks Jan

Hi Jan,
For me ask, I want implement spi+dma, but I not found example for this not same as of cc3200 have example dma+spi.
Thanks
Nguyen

Hi Nguyen,

I am not aware about the ready-to-use SPI example with DMA. Cause I don't use TI Drivers for SPI, I am not able provide exact answer.

You may to search e2e forum for more resources for SPI DMA implementation or you could wait for answer from TI or other community members.

Jan

Hi Jan,
So can I use example github.com/.../cc3200_dma_spi_example on board cc3220modasf
Thanks
Nguyen

Hi Nguyen,

Yes, you can but it may to be slightly complicated. This example CC3200 use driverlib library. This is not a big issue cause driverlib is still available at CC3220. At CC3220 devices was changed default peripheral library to TI Drivers. TI Drviers and drvierlib cannot't be used at same moment at same peripheral. From this reason you need configure TI Drivers to not be SPI controlled by TI Drivers (you need to remove 2nd SPI interface from TI Drivers configuration; 1st SPI interface is for communication with NWP which is intended).

Jan

Hi Jan,
So how can I use dma with spi, I must enable or use somewhat in TI Drivers.
Thanks
Nguyen

Hi Nguyen,

You have two options:
- use driverlib, in this case will be usage of driverlib same as at CC3200
- use TI Drviers (recommended at CC3220). In this case need to be TI Drivers properly configured to DMA usage. Doxygen generated documentation for TI Drviers is at \docs\tidrivers\ in CC3220 SDK.

Jan

Hi Jan,
For me ask?
In source/ti/drivers/SPI.c have bitRate :
const SPI_Params SPI_defaultParams = {
SPI_MODE_BLOCKING, /* transferMode */
SPI_WAIT_FOREVER, /* transferTimeout */
NULL, /* transferCallbackFxn */
SPI_MASTER, /* mode */
1000000, /* bitRate */
8, /* dataSize */
SPI_POL0_PHA0, /* frameFormat */
NULL /* custom */
};

If me change bitrate (1000000 to 200000000) as below, I will must build kernel?
const SPI_Params SPI_defaultParams = {
SPI_MODE_BLOCKING, /* transferMode */
SPI_WAIT_FOREVER, /* transferTimeout */
NULL, /* transferCallbackFxn */
SPI_MASTER, /* mode */
200000000, /* bitRate */
8, /* dataSize */
SPI_POL0_PHA0, /* frameFormat */
NULL /* custom */
};
Thanks
Nguyen