I am trying to use the inbuilt Clocks tool within MCUXpresso to configure the clocks for the FROHF96 functional group, for the LPC55S69EVK board. I want to use PLL1 with the SD card, so I can run this block at 50MHz (as opposed to using the FROHF96MHz clock, which will only allow me a maximum speed of 48MHz). I do not want to use PLL0 as this is already tied up running an I2S dma block.
If I configure PLL0 in the clocks tool, to use the XTAL32M clock running at 16MHz, and multiply and divide this to produce a 150MHz output, and then feed this to the SDIO block, and divide it by 3 to generate a 50MHz clock on the SDIO input, this configuration works.
If, however, I configure the PLL1 block in EXACTLY the same way, connect THIS to the SDIO block, and update the code accordingly, the frequency I read back from the sd block is 0Hz, and the sd card no longer properly functions. (See photo below for set-up within the MCUXpresso clocks tool).
Additionally, I cannot set up the multiplier of either PLL exactly how I would like for other purposes; if for example, I wanted to boost the sdio speed to 52MHz, I would need to activate the 1MHz FRO, connect this to whichever PLL, and then multiply by 52 in the PLL...however, whenever I try changing this multiplier number to 52, the software crashes.
Any help much appreciated.