TMS570LS1224: SPI Issue at less than 1ms rate

Hi Sachin,

I am not familiar with Matlab S-function. If the baud-rate of 2000khz is used, sending 20 words (16-bit each) will take at least 160us. How doesn't your s-function poll the TX or RX status? Is interrupt used?

We are the master and we are trying to read the slave chip via SPI. We are using only internal clock as a trigger to read the SPI data. Read SPI does not work less than 1 ms. Is there any HALOCGENconfiguration setting we should look into. Currently we are reading SP15 and we have configured Data Format2, 

Hi Sachin,

For SPI slave to send data, the SPI master has to provide the SPI clock to slave device. 

If the slave wants to transfer 8 bytes of data, the SPI master can transmit 8 bytes dummy data to slave, and the slave uses the clock to transmit 8 bytes to master. Did you SPI master generate a proper SPI clock?

Hi QJ,

SPI5 is the Master. Please see the attached images of the SPI5 clock config

.

We have tried two methods

1. With CRC calculation
2. Without CRC calculation

Two APIs are used from Halcogen spiTransmitData, spiTransmitAndReceiveData. Since it was slow we tried to use another wrapper by calling only spiTransmitAndReceiveData, Which also took 9.6us to give output.

Why it is taking 10us to execute? By math it should take only 1.6us execute ( The chip at the slave side need 16 clock cycle to transmit the data). Can you think of any other reasons why the APIs take too much time than expected?

@QJ Wang Any clue on what is going wrong?