Kinetis Microcontrollers中的主题 Re: MKL28Z SRAM question

MKL28Z SRAM question

benwang — Mon, 08 Feb 2021 05:46:43 GMT

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?

Re: MKL28Z SRAM question

ErichStyger — Mon, 08 Feb 2021 06:14:32 GMT

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

Re: MKL28Z SRAM question

benwang — Mon, 08 Feb 2021 12:29:05 GMT

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

Re: MKL28Z SRAM question

ErichStyger — Mon, 08 Feb 2021 12:47:16 GMT

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

Re: MKL28Z SRAM question

mjbcswitzerland — Mon, 08 Feb 2021 13:50:32 GMT

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

For professionals searching for faster, problem-free Kinetis and i.MX RT 10xx developments the uTasker project holds the key: https://www.utasker.com/kinetis/FRDM-KL28Z.html

Re: MKL28Z SRAM question

benwang — Tue, 09 Feb 2021 03:19:29 GMT

@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

Re: MKL28Z SRAM question

mjbcswitzerland — Tue, 09 Feb 2021 03:24:45 GMT

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

Re: MKL28Z SRAM question

benwang — Thu, 11 Feb 2021 09:56:06 GMT

Thanks for your confirmation.