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About QN908x SPI slave

Question asked by jinjee seo on Oct 21, 2019
Latest reply on Nov 5, 2019 by jinjee seo

Test environment:
- spi slave: QN9080-DK board
- spi master: ti cc2640r2 development kit

SPI Settings
- data length: 8bit
- clock hz: 400kHz to 4MHz
- source code: modified qn908xcdk_driver_examples_spi_interrupt_transfer example

The spi test was conducted in the above environment.
From 400kHz to 2MHz, the reception was successful without missing data.
The problem is that at 4 MHz, the data is broken.

See the attachment for the SPI waveform.

Question 1
a. Can I use 4Mbps as an interrupt method?
b. Is 4Mbps reception possible using DMA?

Question 2
a. Is it possible to receive continuous data without interruption by DMA (SPI Slave) method?
   - Master constantly transmits data at 2Mbps.
   - DMA buffer size is 256.
   - When tested using the example, data is missing because of the time it takes to operate the DMA again after the DMA reception is completed.