topic Re: SRAM Lower in MCUXpresso SDK

SRAM Lower

AsafTv — Tue, 15 Mar 2022 12:48:14 GMT

How do i use SRM Lower the compile generate link error .heap will not fit in region SRAM_UPPER

can i put heap in SRAM_LOWER?

advice

Re: SRAM Lower

vicentegomez — Wed, 16 Mar 2022 17:39:40 GMT

Can you please tell us the part number that you are using?

Thanks

Re: SRAM Lower

AsafTv — Wed, 16 Mar 2022 18:10:40 GMT

mk64fn1m0xx12

Re: SRAM Lower

AsafTv — Wed, 16 Mar 2022 18:14:00 GMT

i want the compiler use both RAMs as one RAM without ak me for that.

what is the usage those RAMs?

why upper and lower?

There is advantage for each RAMs?

Re: SRAM Lower

ErichStyger — Wed, 16 Mar 2022 18:53:22 GMT

You might have a read at the following articles and the discussions there:

https://mcuoneclipse.com/2013/07/10/freertos-heap-with-segmented-kinetis-k-sram/

https://mcuoneclipse.com/2017/09/18/using-multiple-memory-regions-with-the-freertos-heap/

Basically the reason is that there are two/multiple mermory controllers. That way a better memory performance could be achieved.The important point is that you shall not combine the two memory areas, to prevent a variable/object crossing that memory boundary. Otherwise you will see a hard fault.

More details in the above articles, and as well ways how to use both memory areas.

I hope this helps,

Erich

Re: SRAM Lower

AsafTv — Thu, 17 Mar 2022 04:31:54 GMT

how do i place parameters in SRAM LOWER

all the parameters placed automatically in SRAM Upper.

Re: SRAM Lower

ErichStyger — Thu, 17 Mar 2022 04:39:44 GMT

See the articles I have posted. It depends on the tool chain used, but in essence you can change/modify the linker file for this.

Re: SRAM Lower

AsafTv — Sun, 20 Mar 2022 16:10:15 GMT

what is the way to place const struct in fix address in flash?

the way to do it in IAR is @#pragma location=0x3000

How to do it in gcc?

Re: SRAM Lower

DanielRuvalcaba — Fri, 25 Mar 2022 22:59:38 GMT

Hello,

Please take a look to these websites. I believe you can find useful information that might help you.

https://developer.arm.com/documentation/ka002853/latest

https://community.nxp.com/t5/Kinetis-Microcontrollers/Store-a-variable-in-ROM-FLASH/m-p/328690

Have a good day, Daniel.

Re: SRAM Lower

AsafTv — Mon, 28 Mar 2022 10:03:05 GMT

Place Parameters at fix address in flash for example const uint8 buf[10] in address 0x3000

advice

Re: SRAM Lower

AsafTv — Mon, 28 Mar 2022 10:30:23 GMT

const uint8 buf[10] __attribute__ ((section(".ARM.__at_0x3000"))) = {0xAA,0xaa......};

is not work

advice

Re: SRAM Lower

DanielRuvalcaba — Mon, 28 Mar 2022 23:00:01 GMT

I can see that you are declaring an array and storing data at the same time. Could you please try declaring the variable with the desired address first, and once it is declared, store the respective data to the variable?

Also verify that the address is not overlapped with your code in RAM.

Regards, Daniel.

Re: SRAM Lower

AsafTv — Tue, 29 Mar 2022 18:49:02 GMT

i try to place const param in fix address (FLASH)

Re: SRAM Lower

DanielRuvalcaba — Fri, 01 Apr 2022 23:14:10 GMT

Hello,

I just tried the following example and it worked on my side. Could you please help us verify that you are trying to write in a valid memory address?

const uint8_t TEST[4] __attribute__((aligned(0x00004000))) = {'T', 'E', 'S', 'T'};

Regards, Daniel.

Re: SRAM Lower

AsafTv — Sun, 03 Apr 2022 09:35:56 GMT

Hi,

Thank you for your help.

this line is not work the address i get in the map file for my const param is 0x20000

Re: SRAM Lower

DanielRuvalcaba — Wed, 06 Apr 2022 21:33:20 GMT

I’m dropping you some information that can be useful to solve your problem.

You will probably need to modify the linker file.

https://mcuoneclipse.com/2012/11/01/defining-variables-at-absolute-addresses-with-gcc/

https://mcuoneclipse.com/2016/11/01/getting-the-memory-range-of-sections-with-gnu-linker-files/

https://community.nxp.com/t5/S32-Design-Studio/How-to-wirte-the-data-to-absolute-address/m-p/782831

Best regards, Daniel.