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MSP430FR6979:SPI Highest speed

Part Number: MSP430FR6979

dear champion

I want to know the highest speed,in the first page of datasheet,you said 10MHz.

but it can be clocked by SMCLK, if i set SMCLK 16MHz, what will my SPI.

Best Regards

Emma

  • From section "31.3.6 Serial Clock Control"  of the User's Manual:

    "With UCBRx = 0, the maximum bit clock that can be generated in master mode is BRCLK."

    From Figure 31-1 on page 796 of the User's Manual, BRCLK is the output of the mux that includes SMCLK.

    So, yes, you can run your SPI at 16MHz. However, your connection and peripheral device might not support this speed.

  • Hi Emma,

    Your input for the part number is MSP430FR6979, but your screenshot of datasheet(SLASE23E) is not the datasheet for FR6979. could you help to confirm which part you are using?

    But I will confirm with our system team of the 10 Mbps message of SLASE23E, which is the datasheet of FR6972 and others. I will get back as soon as I confirmed with team.
  • Wei

    it is my fault, it is FR6972 which I am asking.

    Emma

  • Hi Emma,

    For the first page message 10MHz, I still need to check with our system owner to give you confirmation.

    Let me clarify the concept for highest rate:

    The clock source which input to SPI is the feUSCI = 16MHz for maximum, which is the clock rate of SPI module runs. The bit rate is the fUCXCLK which is the rate of the SPI bus clock.

    But the SPI highest bit rates is depends on both master and slave side, which means both side devices of the SPI bus. You could calculate the fUCxCLK by the equation in Table 5-19's note1.

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