I have a small TFT display connected to my iMX6UL board and I'm using the SPI interface to transfer the data. I have everything working but I'm looking to increase the data transfer speed. The SPI transfer is using DMA but when I look at the data transfer signals on a scope there is a significant gap between each 64-byte transfer. You can see this in the image below. A 64-byte transfer takes around 30uS and there is a 15uS gap before the next transfer takes place. This is all happening within the DMA transfer which is transferring a total of 138240 bytes.
Does anybody have any ideas on how to decrease this gap?