AnsweredAssumed Answered

Kinetis MCU Problem

Question asked by Mustafa TARHAN on May 28, 2019
Latest reply on May 30, 2019 by Jing Pan

Our customer is programming MK20DX128VLF5  by using Kinetis Design Studio 3.0.0 


They would like to store data in FlexNVM and later on want to transfer this data to USB. In the same time, they are using ADC, Flex Timer and Uart modul in the same project.

They have seperated in to 24kb D-flash and 8kb for eeprom backup for data storage. Flex NVM space has been identified as you can see in the attached .ld file.


They were able to write and transfer data in the code at 0x1000. Code size has been increased since they want to use UART module and later on they need to optimize it. see optimization options in the attached file.

They did not face with any problem after optimisation. They have changed the data amount from 0x1000 to 0x6000.

After this change, device reset it self while transferring data to USB.

The reason was SW reset because of the code. When they check from debug window, then they saw attached result.

However, this USB commands are not changing as you can see in the .ld file


There are some questions that they have.


1-) what is the IDE that you suggest for the new project? does our mcu support MCUXpresso IDE?

2-) Used RAM and flash size calculation? In the internet it was calculated as below.

 text+data = Flash size; bss+data = Ram size.

Is it true? is there any way to see RAM and flash size as % or any other format .map file or in IDE? 

3-) What is the max stack and heap size? can we visiulase requested or needed size?

4-) How can we make code optimisation and make sure that this optimisation does not brake our code?