RE: SPIM3 sending wrong data/byte

ovrebekk — Mon, 17 Jun 2019 13:00:16 GMT

Have you tried to use SPIM0, 1 or 2 instead to see if the problem is the same?

It is possible that you are affected by Errata 198, which affects the SPIM3 module and can lead to data corruption.

The workaround to this issue as explained by the errata is to put the SPI TX buffer in a separate RAM block to that used by the MCU.

For instance the RAM7 block, located at address 0x2000E000, would normally be free:
https://infocenter.nordicsemi.com/topic/ps_nrf52840/memory.html?cp=3_0_0_3_1

For more information regarding putting variables in specific memory ranges there are some existing devzone cases that you can use for reference, such as this one.

Best regards
Torbjørn