I'm looking for a low cost USB controller with 32-bit SPI series ports.
Yes this is a way, but your solution will need CPU involvement frequently..
some 16-bit ADC or DAC needs 24-bit CMD/data in one SPI CS period.
My assumption is: start the SPI then CPU go to deal other works. uC works efficiently.
May you tell me your a few of your uC's which are capable of 32-bit SPI but low cost?
Hi Larry!
If you dont want to interact with the processor you can use DMA.
Anyway max SPI speed is the BUS/2 and 1 trasnsaction(8 bit) is BUS/16 that will not demand a lot of CPU power. Even more you have an FIFO on both TX and RX so you can put your 24 bit data there and wait for tx-interrupt that will lead to BUS/48 in the interrupt mode.
MKL 26 is a good choice-low cost and it' USB is crystalless.
I hope it help,
Regards Alexey.