nRF52832 (SDK 11.0.0): How to Share Peripheral IDs SPIM0 & TWIM0

[Sami]

Hello,

I've seen some conversations around the forum for applications that must share the same ID. My application must share SPIMO and TWIMO (ID 3, base addresss 0x40003000). I Went ahead and enabled PERIPHERAL_RESOURCE_SHARING_ENABLED, but then the SPI initialization fails with "NRF_ERROR_BUSY" (in nrf_drv_common.c, in function call "acquire_shared_resource()" ). Apparently, the NRF_ERROR_BUSY is expected. Is there sample code or a white paper that can advice me what to do? Do I simply need to disable TWIM0 while SPIMO is initializing? I'm not really sure how to proceed. Also what are implications around interrupts ? Thank you.

[Hung Bui]

Hi Sami,

Could you explain a little bit more why you "must" use the peripherals that share the same ID ? Do you have multiple SPIs and TWIs that you can't avoid using peripherals with same ID ? If not I would suggest to use peripheral with different IDs.

[Sami]

Hi Hung, Thank you for your quick reply. We have more peripherals than available base addresses in our system. After learning that we have to initialize and un-initialize shared Instances, we too decided to avoid the "enable shared peripherals" flag. The nRF52832 doesn't gracefully allow us shared peripherals. Rather, we decided to multiplex certain peripherals on the same physical pin so as to avoid the need to share peripherals.

[Hung Bui]

I haven't tried myself the "shared peripherals" option.

But if you plan to use multiple external peripheral on one same internal peripheral, you can use different physical pins and can reconfigure the pin dynamically in the code. I'm not sure why you want to connect them to the same physical pin (and then do multiplexing externally ? )