nRF52340 USB SPI3

[TobiasLaut]

 Initializing the USB inerterface blocks the SPI3 interface. The SPI3 is not responding to any commands like reset. We do not use any SPI interrupts, just read the registers. Do you have a solution for this problem?

[Turbo J]

You probably triggered the SPIM3 errata - see errata sheet.

[TobiasLaut]

Thank you for your help. We checked for all possible Errata. We do not use PPI, thus the only possibility is the EVENTS_END bug [193]. The SPI3 communication stops working after connecting the device via usb to a windows PC. 

[TobiasLaut]

*(volatile uint32_t *)0x4002000 = -1 improves the situation but does not solve it completely  

[Simonr]

Hi

Please note that the workaround does not set 0x4002000 = -1, but is implemented as shown below:

 *(volatile uint32_t *)0x4002FFFC = 0; 
 *(volatile uint32_t *)0x4002FFFC; 
 *(volatile uint32_t *)0x4002FFFC = 1; 

Can you try to decrease the frequency you're using the SPI3 to see if that helps at all? 

Due to the summer vacation period here in Norway, we are low on staff at the moment, so delayed replies are expected. Sorry about the inconvenience!

Best regards,

Simon