SPI Consumption problem

RE: SPI Consumption problem

Ole Bauck — Tue, 02 Aug 2016 08:42:03 GMT

You can see if it uses DMA by checking (if 1 it uses DMA):

#define SPI1_USE_EASY_DMA 1
#define TWI0_USE_EASY_DMA 1

Do you see current increase with SPI0 and TWI1 (when DMA is enabled)?

RE: SPI Consumption problem

Cristian — Sat, 30 Jul 2016 00:52:52 GMT

Yes, I meant SPIM, but in "nrf_drv_config.h" theres is no define for SPIM, that why I use SPI. I've double cheked, and I'm getting around 420uA using this defines on "nrf_drv_config.h":

#define TWI0_ENABLED 1
#define SPI1_ENABLED 1

I'm not sure about DMA enabled, as I've just used the drv functions.

RE: SPI Consumption problem

Ole Bauck — Thu, 28 Jul 2016 13:34:47 GMT

We have seen issues with SPIM0/1 and TWIM0/1 regarding this. The relevant errata for this can be found here. We are still investigating this issue so it does not cover all use cases that will lead to increased current consumption (like using SPIM0/1). When we have more information we will update this issue.

When you say SPIO or SPI1 you mean SPIM0 or SPIM1? We thought this issue was only with the DMA enabled SPI or TWI peripheral (SPIM/SPIS/TWIM/TWIS). It is also strange that you don't see any problem with SPIM1 as this should also cause the current increase (only SPIM2 should not cause the current increase).

RE: SPI Consumption problem

Cristian — Thu, 28 Jul 2016 03:12:19 GMT

I've tried changing to SPI2, but consumption changed just 50uA. Then I tried disabling TWI1 from nrf_drv_config.h (being that I already removed any call to twi driver) and now current consuption is as expected !!. Anyway, I could not achieve this current with SPI0. Just SPI1 and SPI2 are correct. I even was able to configure TWI0 without problem. Is there any difference on SPI0? Is there any known conflic between SPIx and TWI1?

RE: SPI Consumption problem

Ole Bauck — Mon, 25 Jul 2016 15:39:46 GMT

Can you try to use SPI instance 2 instead:

#define SPI_INSTANCE  2

and see if the current consumption goes down?

RE: SPI Consumption problem

Cristian — Fri, 22 Jul 2016 01:16:36 GMT

Hi, Thanks for your comments.

I`ve followed your advise and disable everything (except for the timer) and power went down to 30uA. So the first thing I enable again was the advertising, and consumption return to 800uA. I imagine there is some interaction, but I dont know how to fix it. I've tried enabling DCDC and also stopping HFCLK on the interruption routine. (by the way, I've debug CLOCK registers and HFCLK is being disable correctly after transfer ends, with no need to call "sd_clock_hfclk_release()")

Any thoughts?

RE: SPI Consumption problem

Ole Bauck — Wed, 20 Jul 2016 11:14:33 GMT

It sounds like HFCLK is running all the time which leads to a current increase of 400-450uA. When the SPI transaction is done it should release the clock and the current should go down to what it was before the transaction.

Try to only run the SPI code and see if the behavior is the same.

PAN 23 is only present on rev A chips (PCA10036) so no need to worry about that.