nRF52 GPIO DMA

[af2377]

Hello,

Is it possible to use easyDMA to transfer from GPIO to memory without involving the CPU? We need to read from a parallel bus for a short duration, without losing any data. Additionally, what is the maximum input data rate to the GPIO, i.e. how fast is the GPIO sampling clock?

[MartinBL]

Hi,

Unfortunately not. I can't think of any hacks to achieve it without involving the CPU either. The best solution I can think of is to use some sort of parallel to serial SPI converter chip. The SPI has easyDMA, but obviously can't reach the same data throughput as a parallel bus. Max bitrate for the SPI is 8 Mbps.

[SRA]

Does the Cortex M4 in the nf52 have bit banding?

[af2377]

thank you for the answer.

[RK]

No the cortex M4 in the nRF52 does not have bit-banding, not that I can think why it would matter. The capabilities of the chip are listed in the documentation, including which of the M4 ARM optional features are and are not implemented.