TMS320F28377S: Copying Flash API to RAM, after used how to release

Jordan Zhou

Hi,

Customer is using F28377S for their application.

Because of RAM size, customer calls and runs Flash API in Flash, to erase other sectors. Most of the times, it works. I don't know how to explain to customer.

At the same time, they are suggested to copy and run the API to RAM. But RAM size is not enough. Is there any way to copy API to RAM, after used release RAM?

Thanks a lot.

Br, Jordan

over 9 years ago

0 Vamsi Gudivada over 9 years ago

TI__Guru* 87155 points

Jordan,

Since there are two Flash banks in F28377S, user can execute the Flash API from one bank to erase/program the other bank. Flash API should not be executed from the same bank on which an erase/program operation is targeted.

Thanks and regards,
Vamsi

0 Jordan Zhou over 9 years ago in reply to Vamsi Gudivada

TI__Genius 10470 points

Vamsi,
Sorry, there's a mistake.
Customer is using F28374S. There's only one bank. Flash API is executed in the same bank on erase/program. Most of the times, it works fine.
Br, Jordan

0 Vamsi Gudivada over 9 years ago in reply to Jordan Zhou

TI__Guru* 87155 points

Jordan,

If it is F28374S with one bank, Flash API must be executed from RAM. I understand it may work some times but executing the API from Flash when erase/program is in progress on it can cause race conditions and undefined behavior. Hence, TI suggests to execute the Flash API from RAM only in this case.

Thanks and regards,

Vamsi

0 Jordan Zhou over 9 years ago in reply to Vamsi Gudivada

TI__Genius 10470 points

Vamsi,
If customer moves Flash API to RAM, is there any way to release these RAM locations for other use, after Flash operation?
Br, Jordan

0 Vamsi Gudivada over 9 years ago in reply to Jordan Zhou

TI__Guru* 87155 points

Jordan,

Yes. Once the Flash operations are over, RAM can be used for other purposes. Since Flash API will be part of user's Flash image, they can copy it to RAM when needed again.

Thanks and regards,
Vamsi

0 Jordan Zhou over 9 years ago in reply to Vamsi Gudivada

TI__Genius 10470 points

Vamsi,

Thanks for your info.

Two questions:

1) Flash API is copied to RAM in *.cmd. How to release these RAM?

2) Flash API is copied in code by memorycopy(), how to release these RAM?

Br, Jordan

0 Vamsi Gudivada over 9 years ago in reply to Jordan Zhou

TI__Guru* 87155 points

Jordan,

Once Flash API execution is over, application can call memcpy() again with a new set of symbols for loading the new code.

For example: You can do as below in linker command file:
NewCode : LOAD = FLASH_x,
RUN = RAM_x,
LOAD_START(_NewCodeLoadStart),
LOAD_SIZE(_NewCodeLoadSize),
LOAD_END(_NewCodeLoadEnd),
RUN_START(_NewCodeRunStart),
RUN_SIZE(_NewCodeRunSize),
RUN_END(_NewCodeRunEnd),
PAGE = 0, ALIGN(4)

You can declare above external symbols in your header file as below:
extern Uint16 NewCodeLoadStart;
extern Uint16 NewCodeLoadEnd;
extern Uint16 NewCodeLoadSize;
extern Uint16 NewCodeRunStart;
extern Uint16 NewCodeRunEnd;
extern Uint16 NewCodeRunSize;

In your code, you can call memcpy(&NewCodeRunStart, &NewCodeLoadStart, (size_t)&NewCodeLoadSize) after the Flash API usage is over.

Thanks and regards,
Vamsi

0 Jordan Zhou over 9 years ago in reply to Vamsi Gudivada

TI__Genius 10470 points

Vamsi,
This is a way to call other functions in the same RAM.
Can the RAM be used for application all kinds of parameters?
Br, Jordan

0 Vamsi Gudivada over 9 years ago in reply to Jordan Zhou

TI__Guru* 87155 points

Jordan,

I think you are asking whether you can use the freed up space for data or not. Since you will be defining that space in Page 0 for API, I think it is better to use that space for code. If you want to use it for data, may be you can use a pointer to point to the freed up space.

Thanks and regards,
Vamsi

0 Vamsi Gudivada over 9 years ago in reply to Vamsi Gudivada

TI__Guru* 87155 points

Jordan,

Did the customer try the suggestion of calling memcpy() again with a new set of symbols for loading the new code? Did it work for them? Just curious.

Thanks and regards,
Vamsi

0 Jordan Zhou over 9 years ago in reply to Vamsi Gudivada

TI__Genius 10470 points

Vamsi,
Customer didn't try this, as they were not confident with the new logic.
Br, Jordan

0 Vamsi Gudivada over 9 years ago in reply to Jordan Zhou

TI__Guru* 87155 points

Jordan,

Thank you for the update. I am closing this ticket.

Regards,
Vamsi

0 Jordan Zhou over 9 years ago in reply to Vamsi Gudivada

TI__Genius 10470 points

Vamsi,
For F28x7x, what's the usual way to write the CSM password in user application? In F2833x, there's CSMPassword.asm. What about F28x7x?
Thanks a lot.
Br, Jordan

0 Vivek Singh over 9 years ago in reply to Jordan Zhou

TI__Guru** 117431 points

Hi Jordan,

For F28x7x, what's the usual way to write the CSM password in user application? In F2833x, there's CSMPassword.asm. What about F28x7x?

For this device it's same method. Please refer example "blinky_with_DCSM" in control suite for this.

Regards,

Vivek Singh

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F28377S: Copying Flash API to RAM, after used how to release