TDA4VM: SPI max data speed rate

Hi,

Yes, SPI supports at max 50Mbps speed in HW. Speed in SW is highly dependent on the load.

Regards,

Brijesh

Hi Brijesh,

Sorry, I am not very familiar with SW. Could you plz explain what the meaning of "dependent on the load" is? Or, is there any imitation on SPI achieve max speed rate?

Besides, I would like to confirm it is 48M rather than 50M, right? 

Hi xingyu Zhu,

SW load here mean, how fast we are able to submit the request to achieve full 50Mbps speed. Individual words will be transmitted at max 50Mbps speed, lets say if we submit 8 bytes to SPI to transmit to remote device, they will be transmitted at 50Mbps (if divider is set to 1)..

As we can see inputClkFreq variable in ti-processor-sdk-rtos-j721e-evm-08_05_00_11\pdk_jacinto_08_05_00_36\packages\ti\drv\spi\soc\j721e\SPI_soc.c, it is set to 50MHz, so the max baud rate is 50Mbps.

Regards,

Brijesh 

Hi Brijesh,

Thanks for your quick reply. Understood, in SDK, it says 50MHz. Then how to understand the Max Clock Rates in TRM shown in my previous reply.

Besides, in DS, based on cycle time, it can be calculated that max frequency is about 48MHz. 

Hi Xingyu Zhu,

That's correct. specs requires change.. I will check with the our team and try to get it fixed.

Regards,

Brijesh