CCS/TMS320F28388D: BOOT TIME

Nagesh,

This info is available in device datasheet (please see the snapshot below) -

Regards,

Vivek Singh

Vivek,

Thank you for your response.

Can you explain how was this measured if you can provide the steps to measure it?

we currently have an external watchdog with 10ms which is not getting refreshed within 10 ms only on power up.

Can you please let us know if we are missing something on power up because of which its taking 14 ms to reach our flash code. (boot to flash)

thanks,

Nagesh

Nagesh,

That time is from XRSn going high to CPU executing Ist code in flash. This does not account for power up time since that depends on board components. Hope this helps.

Regards,

Vivek Singh

Hi Vivek, 

I have another doubt, according to the TRM it has a boot from code on the F28388D controller.

can you let me know how time does it take to execute the boot from code.

thanks,

Nagesh

Nagesh,

Sorry, I did not quite understand your query. Can you provide more detail about your query?

Regards,

Vivek Singh

Hi Vivek, 

We do not have much of hardware changes on the board, its just the power supplied to the F28388D controller.

I got a doubt the datasheet mentions Reset to FLash is 1.2ms, then what is the time taken by the F28388D controller from power on to the Reset. can you please guide us if we can reduce the time to less than 10ms , if you can connect us to boot expert will be helpful

Thanks,

Nagesh

Nagesh,

The expert assigned to this thread (Chris C) is on vacation and will be back in the office Jan 4. We appreciate your patience during this holiday season.

Thanks,

Sira

Nagesh,

 what is the time taken by the F28388D controller from power on to the Reset.

This info is also provided in same table "7.10.2.2.2 Reset (XRSn) Switching Characteristics". Parameter name is tw(RSL1) and it's value is 100 uS (TYP). 

Regards,

Vivek Singh

Hi Vivek, 

From the section "5.8.2.2 Reset Electrical Data and Timing  " of the f28388D device datasheet.

We can see the execution of boot ROM happens after the XRSn is high after the boot ROM  user code is executed.

We are using FLASH Sector 0 boot and no other peripheral booting is selected, hence GPIO72 and GPIO84 are set high.

what will be time taken during the boot mode pins to reach the user code?

Hi Vivek, 

when we measured the time taken from boot to flash it is not showing 1.2 ms, it is taking 15ms.

can you let me know where can I find the code for this boot code execution? 

basically, I want to understand where could I have gone wrong.

if you can help me with any example code where you have verified that it's taking 1.2ms will be very helpful so that I can compare it with my code. 

thanks,

Nagesh 

BOOT code is available in C2000Ware (<C2000WARE>\libraries\boot_rom\f2838x\revA\rom_sources).

If you have scope snapshot of this time, please share it.

Regards,

Vivek Singh

Hi Vivek, 

I am using compiler version 18.1.3.LTS on the CCS IDE  Version: 10.1.0.00010 .

i have modified the compiler flags to generate the build-in EABI format as the IDE does not support compiler version 18.1.3.LTS to generate EABI/ELF format.

could this have a problem?

thanks,

Nagesh

Hi Vivek, 

I noticed one more behaviour today when verified with the example code of Led_ex1_blinky from Ti, the time taken from XRSn to main is 4ms but in my application the XRSn to main is 15 ms not able to find out the where could be the issue any pointers to look for will be helpful.

attaching the screenshot of the trigger

TI example Led ex1 blinky program modified to verify boot time with gpio145

My application  is taking 15ms of boot time after the trigger attached in zip file I was not able to upload one more image

screenshot.zip

Hi Nagesh,

Main() is not the entry point for the application. It is code_start() which is part of f2838x_codestartbranch.asm. Code_start function has _c_int00 function call which initialize all the variables in your application and it can take significant amount of time depending on number of variables.

Regards,

Vivek Singh

Hi Vivek, 

thank you for the suggestion.

I changed in the linker from rom_model to ram_model after this change the boot time taken is less than 2ms.

this drastic decrease in time is something trying to figure out, but I would like to know what will be the major impact if I change to ram_model.

i will be using my application as a standalone application.

thanks,

Nagesh

Nagesh

You can read more on the two models in section 3.3 of this guide: https://www.ti.com/lit/spru513 

Best regards

Chris

Hi Chris. 

thank you for the reference.

I understand from the document for the stand-alone application I need to use ROM Model.

Now that my application is taking 14 ms from power up to main() function.

can you let me know what could be the areas I can look for so that I can reduce the boot time in my application .

Like removing Global variables initialization will this help?

as per section 3.3.1 The _c_int00 Function point#3

thanks,

Nagesh

Nagesh,

Yes, definitely reviewing your global variables, both initialized and not, but with focus on the initialized ones first.

Best regards

Chris

Hi Chris, 

Thank you, this reduced the boot time by removing the initialization of variables.

But now that I want to keep the global variable initialization so that it will not be a huge rework for me from the code aspect.

So I would like to know if we can modify the boot28.asm file to toggle the GPIO46 with 0.5us pulse, in between where the auto initialization of the variable is going on .

can we update the boot28.asm code ? 

thanks,

Nagesh

Nagesh, help me understand better - is your issue resolved, or are you still looking for help?