QN9080: Which max data transfer speed from 8-GPIO to RAM through DMA excluding all slowing factors (ideally)?

[karlin_egor]

Hello everyone,
We plan to use in our projekt QN9080. And the question of the speed of data transmission through DMA is key moment for us. In general we have next question: Which max data transfer speed from/to 8-GPIO to/from DMA-RAM excluding all slowing factors (ideally)?

We plan to use the following mode:

1. Update rate 8-GPIO is 32 MHz.
2. CLK_AHB, CLK_GPIO and CLK_DMA is 32 MHz
3. We use only  one DMA chanel . Others DMA chanels are disabled.
4. All other peripherals are disabled.
5. We transfer only 1 kb to RAM, and then processed this data.

We plane to use it for transfer from external ADC with clocking frequency 32 MHz.

I plan to use following configure:

PERIPHREQEN 0
HWTRIGEN 1
TRIGPOL 1
TRIGTYPE 1
TRIGBURST 1
BURSTPOWER 1010
SRCBURSTWARP 1
CHPRIORITY 0

XFERCFG

WIDTH 0x0
SRCINK 0x0
DSTINC 0x1

1) Can we transfer data without error on speed 32MB/s, if we use this  configure?
2) Which configure can we use to transfer data on this speed?

3) Can the chip provide an estimated speed of 32 or 16 or 8 Mbytes / s?

Datasheet and user manual don't contain this information.

Thanks in advanced,
Egor

[estephania_mart]

Hello,

The maximum speed depends on AHB speed, DMA latency and bus arbitration priority. 32MB/s can be very challenging as our max speed is 32M. 

You will need to write a simple test program to test the actual speed on SDK example:

\boards\qn908xcdk\driver_examples\dma\memory_to_memory.

Regards,

Estephania