I'm trying to initialize an SD Card in SPI mode using the fsl_spi module but I am having an issue with how fast I can complete multiple, single-byte transfers. Below is my test code to see the delay between individual single byte transfers. Spi clock is 250khz.
while(1) SPI_DRV_MasterTransferBlocking(FSL_SPICOM1, &spiCom1_MasterConfig0, NULL, NULL ,1, 10);
When I look at the output on my logic analyzer I see a 156 us delay between consecutive transfers even though I am just repeating the same instruction. See analyzer snapshot below.
I believe this long delay between transfers might be causing issue in my SD card initialization as I have tested the same hardware with different code on another setup and I have no issue with the SD hardware itself.
My questions is: is this how the fsl_spi module is supposed to operate or is there a way to implement consecutive single-byte transfers quicker?