Cyw20719B2 RAM Usage / Utility

[HaPo_4773321]

Hello ,

I calculated RAM usage and Utilization in compile time and  RUN time (using wiced_memory_get_free_bytes() API)

I used Empty_BTSDK_App Example Code to Calculate RAM Utility.

As per  Memory Layout Document, RAM should be 448 KB, But I am getting only 274 KB as per below Calculation.

Please find Compile time Data and Calculation below:

• RAM Usage Compile time

Empty_BTSDK_App	Empty BT Application - SDK
			Start	End
Patch Code Size	7604		0x270400	0x277A04
Patch RAM Size	1264		0x2129AC	0x212E9C
Text	400		0x212E9C	0x21302C
Rodata	445		0x21302C	0x2131E9
Data	39		0x2131EC	0x213213
Bss	2		0x213214	0x213216
Setup	128		0x213218	0x213298
RAM USED	1020	B

• Run Time RAM Availability using API.

Start RAM Left

278892

• Total RAM As per Above Calculation

Total RAM	279912	B
	273.3516	KB

Can anyone please tell me where (448 - 273  = 175 KB )  RAM Used ?

Thanks & Regards,

Hardik

[DheerajPK_41 · Accepted solution]

Hi,

The free RAM given by wiced_memory_get_free_bytes() API is the RAM left for the application usage. You can use this much memory for your application logic. The remaining memory is consumed by the ROM initializations, dynamic usages, etc. 

Thanks,

-Dheeraj.P.K

[HaPo_4773321]

Hi Dheeraj,

Thanks for your response.

The remaining memory is 175 KB.  ROM initialization will not take much memory and I am not allocating any dynamic memory in my application. 

Can you please give any reference / Document to Dynamic usages or ROM initialization Memory usage?

Is there any other way i can calculate Usage/ Utilization of memory ?

Thanks & Regards,

Hardik Pokar

[DheerajPK_41]

Hi, 

wiced_memory_get_free_bytes() returns the free memory available after all static and dynamic memory allocation. This can be used for your application logic. Around 100KB will be used bt the FW & Stack initialization till it reaches the Application_init. 

We don't have a document which explains the ROM initialization memory usage.  May I know why do you want to calculate it? 

Thanks,

-Dheeraj.P.K

[HaPo_4773321]

Hi Dheeraj,

I was calculating my Application Buffer Requirement and Available User Space. So I can plan my memory management in that way. 

Thanks & Regards,

Hardik

[DheerajPK_41]

Hi,

I would suggest to go ahead with the memory management planning with the return value given by wiced_memory_get_free_bytes() since it is the actual memory which can be used by the developer for their application logic. 

In wiced_memory.h you can find APIs to monitor the buffer usage as well to track it. Please have a look.

Thanks,

-Dheeraj.P.K