Model-Based Design Toolbox (MBDT)中的主题 Re: DataMemWrite and DataMemRead to access FlexRAM

DataMemWrite and DataMemRead to access FlexRAM

Maciek — Sun, 08 Mar 2020 21:01:19 GMT

Can we write to and read from FlexRAM memory on S32k1xx using DataMemWrite and DataMemRead blocks ?

Thanks

Maciek

Re: DataMemWrite and DataMemRead to access FlexRAM

mariuslucianand — Mon, 09 Mar 2020 11:55:37 GMT

Hello Maciek‌,

The memory blocks DataMemRead and DataMemWrite, allows you on S32K access any memory memory address.

For example, the DataMemWrite Block allows you to write a Pointer Type value at the Address + Offset memory address.

This is the actual generated code

/* write to memory address */
{
<Pointer type> * address;
address = (<Pointer type> *) 0x%<Address + Offset>;
*(address) = <Input Value>;
}

However, I had a look on the S32SDK on the Flash Memory (Flash) Driver and I see that there is a driver that allows the user to write and read the memory as if dealing with an Eeprom using the flash_driver.c. If you have a short working example, I can add support to the functions you call directly from Simulink using custom code, the third method I've told you in the other thread. If not, just give me a few days to provide a working Simulink model.

Hope this helps,

Marius

Re: DataMemWrite and DataMemRead to access FlexRAM

gramirezv — Mon, 09 Mar 2020 19:24:52 GMT

I'm looking to do something similar, I haven't got to get working a short example on the S32 SDK yet.

An example Simulink model would be great to get us started, I'm pretty sure this is a useful feature to have.

Thanks a lot!

Gustavo

Re: DataMemWrite and DataMemRead to access FlexRAM

Maciek — Mon, 09 Mar 2020 23:40:44 GMT

Thanks for Your quick response mariuslucianandrei,

I'm looking forward for Your example model!

I didn't start writing anything yet - I was still reading documentation.

If I understand correctly, there is a way of configuring and using EEPROM without flash_driver. The configuration can be done with appropriate settings of "advanced options" of the debugger in S32DS (program partition command). Then a structure with user data fields can be put directly in FlexRAM region. But this solution seems to have some disadvantages:

- at some point we have to 'exit' Matlab/Simulink and use S32DS

- we have to adjust/change the linker file (I think the linker file used by S32K1xx MBD toolbox has no definitions of FlexRAM regions)

- we still have to write 'driver blocks' for reading/writing the user data structure in FlexRAM

If I'm wrong with the above - please let me know.

In our application, we have non-volatile data that will be re-configured very rarely - so for this writing and reading FlexNVM would be sufficient. But we also have run-time data that need to be saved frequently - for this we need EEPROM functionality. In summary working EEPROM is enough to meet the customer requirements.

If You can prepare a very simple example model with Matlab Function blocks for initial configuration of memory partition and for reading and writing EEPROM (via configured FlexRAM; all of this using flash_driver) it would help us significantly.

Thanks for help

Maciek