MKL28Z SRAM question

[benwang]

Hi, I am taking a lot at the MKL28Z reference manual , and did not about if the internal SRAM(128k) is split into two regions as MKL27Z, which are SRAM_L and SRAM_U?  Does MKL28Z did split into two same size of SRAM_L(64KB: 0x1fff8000~1fffffff) and SRAM_U(64KB:0x20000000~0x20007ffff) as the general feature as other Kinetis MCU? 

[benwang]

@mjbcswitzerland @ErichStyger Thanks for your answer. But still looks like we did not come to agreement about this. It's better we could ask for AE team or IC design team to get the accurate feedback 

[mjbcswitzerland · Accepted solution]

Hi

I have used the KL28 with this SRAM layout so am very sure that it is accurate, otherwise I am sure that the projects would already have failed to run correctly.

This reference has been on line for over three years: https://www.utasker.com/kinetis/FRDM-KL28Z.html using the SRAM as specified with no reports of failure.

Regards

Mark

[benwang]

Thanks for your confirmation. 

[ErichStyger]

Hi @benwang 

To my understanding, only the Kinetis family without the L has a dual memory controller and that's why the memory is split around 0x2000'0000. But the L family does not have such a split:

KL28Z:

KL27Z:

I hope this helps,

Erich

PS: as for the implications of the divided memory on the K devices, there is a discussion on this topic on Using Multiple Memory Regions with the FreeRTOS Heap 

[benwang]

Hi @ErichStyger 

      Thanks for you quick reply. But according to the MKL27Z reference manual, it dos split the SRAM into SRAM_L and SRAM_U, please refer to the page 60.

https://www.nxp.com.cn/docs/en/reference-manual/KL27P64M48SF6RM.pdf

However, I did not find the similar description on MKL28Z, that's why I am a little bit confused about this. Could you double confirm with AE or design team about that? Thanks!

https://www.nxp.com.cn/docs/en/reference-manual/MKL28ZRM.pdf

[mjbcswitzerland]

Hi

The SRAM layout in the KL28 is the same as in all other L parts:
1/4 anchored below 0x20000000
3/4 anchored above 0x20000000

In the manual it is show in two places:

although it is a strange that in the first table the first 1/4 of the SRAM is in the code section rather than in the SRAM section.

Regards

Mark
[uTasker project developer for Kinetis and i.MX RT]
Contact me by personal message or on the uTasker web site to discuss professional training, solutions to problems or rapid product development requirements

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[ErichStyger]

So either the SDK or the RM is wrong, I believe the later (or at least misleading).