2 Replies Latest reply on Dec 29, 2016 10:56 AM by sele_2039411

    SPI clocking on PSOC 4 (CY8C4247AZI-M485)




      I added an SCB SPI channel in one of my projects on the PSOC 4200M of the CY8CKIT-043.


      After some hours of debugging, I figured out that the chip does not clock out new data as it gets written into the transmit register. Data just accumulates in the FIFO.


      So, my guess was to look closer at the clock for the SCB SPI block. Instead of the internal clock (8MHz with a /3 divider from HFCLK, 8 times oversampling), I added an external clock 8MHz. And indeed, now, data gets clocked out correctly.


      I have compared my setup of the SCB SPI channel with the one provided in example "SCB_SpiCommMaster01". In this example, the internal clock works for me. The settings in my own project are identical.


      What could the reason be that in my own project, the internal clock does not get connected (?) correctly to the SCB SPI block? I would prefer using the internal clock source instead of wasting an external clock element.