Low power is not supported with enabled cache, See Appnote: 1234

cancel
Showing results for 
Search instead for 
Did you mean: 

Low power is not supported with enabled cache, See Appnote: 1234

456 Views
danielchai
Senior Contributor I

Hi,

I am tring to use the MQX4.0.2. But after setting MQX_ENABLE_LOW_POWER TO 1 on user_config.h, when compile BSP, it gives me this error:

Low power is not supported with enabled cache, See Appnote: 1234.

But I did not find where is Appnote: 1234.

Any ideas about this? Or how can I disable the cache?

Thanks.

0 Kudos
6 Replies

158 Views
brianpaterson
Contributor III

Daniel,

You ever get an answer to this? Somehow, not surprised as the 4.0.2.2 update is still leaving this hanging out in the wind.

I have the K60F120M with the 1M0 memory and ran straight into this error.

I set, since I really need to, the MQX_ENABLE_LOW_POWER to 1 in the config

I also set, since the bsp is giving errors like crazy, the following in the config:

MQX_DISABLE_CACHE          1

Hey, we'll see if this works.

Let me know if you find anything.

Brian

0 Kudos

158 Views
dereksnell
NXP Employee
NXP Employee

Hi Brian,

Why do you say "4.0.2.2 update is still leaving this hanging out in the wind”?  Earlier releases of MQX used the preprocessor error below in \mqx\source\psp\cortex_m\kinetis.h to prevent users from having the cache enabled when entering low-power mode, to avoid issues with erratum e7166.  But in the latest MQX v4.0.2.2, this has been removed.  And the v4.0.2.1/2 release notes show the workaround was implemented:

ENGR00270143

§ Software workaround for Errata e7166, which is relevant for Mask 3N96B silicon.

§ Affected BSPs: TWR-K60F120M and TWR-K70F120M

#if MQX_ENABLE_LOW_POWER && (PSP_HAS_CODE_CACHE || PSP_HAS_DATA_CACHE)

#error Low power is not supported with enabled cache, See Appnote: 1234

#endif

0 Kudos

158 Views
brianpaterson
Contributor III

Derek,

I still have it in the build - Freescale_MQX_4_0\lib\twrk60f120m.uv4/release/psp/kinetis.h

Lines 162 through 164:

#if MQX_ENABLE_LOW_POWER && (PSP_HAS_CODE_CACHE || PSP_HAS_DATA_CACHE)

#error Low power is not supported with enabled cache, See Appnote: 1234

#endif

This is 4.0.2.2 updated. Sorry.

I plan on installing a clean 4.0.2 install and looking at the 4.0.2.1 and 4.0.2.2 updates to see the differences.

Now, is it possible that my install is messed up? Sure!

It's also been heavily beaten up.

Also, while I have you on the telephone (OK, I know...) my scatter file seems to go nuts every once in a while with the vectors.o FIRST/LAST error. Not sure why... Any ideas? Any relation to using low power / sleep routines?

Thanks!

Brian

0 Kudos

158 Views
richardzieminsk
Contributor II

Can you confirm Low Power Mode(s) are supported now with cache enabled?  I see no mention either way in the app. note (AN4447) you listed.  Would that mean I should comment out/ignore the warming(s) int the BSP? Specifically kinetis.h.

Thanks,

Rich

0 Kudos

158 Views
susansu
NXP Employee
NXP Employee

Hi,

About how to use low power mode, you could refer to AN4447 - Freescale MQX Low-Power Management

http://cache.freescale.com/files/32bit/doc/app_note/AN4447.pdf?fpsp=1&WT_TYPE=Application Notes&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation

0 Kudos

158 Views
BielikM
Contributor III

Hi.

As i know this issue has been fixed(or workarounded) in 4.0.2.2 release.

Regards

0 Kudos