I'm looking for a low cost USB controller with 32-bit SPI series ports.
I decide to select MK22FN512 to use its parallel bus (Flexbus). my question is fixed.
Hi,
So at present, the 32 bit SPI is a bottleneck. Please make reference from the thread below:Transmit 32 Bit via SPI . Hope it is helpful.
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.
Why do you need 32 bits SPI ? You can just send 4 bytes and manually control SS or CS pin with a dedicated gpio.
I know you KL2 series has USB, but its SPI is 8 bits.