CC2650: Missing Documentation for Configuring Cache as GPRAM in BLE SDK 2.02.08.12

Vikas R J

Part Number: CC2650
Other Parts Discussed in Thread: CC2640R2F, CC2640

Tool/software:

We are using BLE SDK 2.02.08.12 for our project with the CC2650 and need to configure the cache as GPRAM. However, we couldn't find any documentation or reference guide in the SDK regarding this configuration.

Could you please provide the necessary documentation or guidance on how to properly configure the cache as GPRAM in this SDK version?

Looking forward to your support.

over 1 year ago

0 Jan over 1 year ago

TI__Mastermind 44770 points

Hi,

I do not believe you are able to reconfigure the cache as GPRAM on the CC2650 device. Have you found documentation that states this is supported? This is a possibility on the CC2640R2 device.

Best Regards,

Jan

0 Vikas R J over 1 year ago in reply to Jan

Prodigy 70 points

Hi Jan,
Thank you for your response. I understand that configuring the cache as GPRAM is supported on the CC2640R2 but may not be available on the CC2650. Given this, I need to port my project to the CC2640R1F.

Could you provide guidance on how to port my CC2650 project to the CC2640R1F and enable cache as GPRAM on this device? Specifically, I’d appreciate any documentation or key modifications required in the linker file, project settings, or SDK configurations to achieve this.

Looking forward to your insights!

0 Jan over 1 year ago in reply to Vikas R J

TI__Mastermind 44770 points

Hi,

Just want to clarify, that you would need to port over to the CC2640R2F to ensure you have that ability. We do have some migration guides available to assist with these changes:

https://dev.ti.com/tirex/content/simplelink_cc2640r2_sdk_5_30_00_03/docs/blestack/ble_user_guide/html/ble-stack-3.x-guide/porting-guides/cc254x-to-cc2640.html

https://dev.ti.com/tirex/content/simplelink_cc2640r2_sdk_5_30_00_03/docs/blestack/ble_user_guide/html/ble-stack-3.x-guide/porting-guides/cc2640-to-cc2640r2.html

Best Regards,

Jan

0 Vikas R J over 1 year ago in reply to Jan

Prodigy 70 points

Hi Jan,

Just wanted to clarify, we are not using CC2640R2.

To migrate our project from CC2650 to CC2640, we referred to this https://e2e.ti.com/support/wireless-connectivity/bluetooth-group/bluetooth/f/bluetooth-forum/533321/migrating-code-from-a-cc2650-to-a-cc2640 .

We are using a custom CC2640 board and initially implemented our application on the CC2650 LaunchPad using the Simple Peripheral example project. The only modification we made was updating the board file. Everything is working fine—we can see advertisements, establish connections, and disconnect successfully.

Current Task:

Now, we need to enable the flash cache as GPRAM on CC2640. However, we couldn't find any relevant documentation in BLE SDK 2.02.08.12.

Questions:

Can we enable the flash cache as GPRAM on CC2640?
If so, what are the steps to enable it?

Note: since you already mentioned that CC2650 does not support reconfiguring the cache as GPRAM. However, we need confirmation on whether this applies to CC2640 as well.

Looking forward to your insights.

0 Jan over 1 year ago in reply to Vikas R J

TI__Mastermind 44770 points

Hi,

Looking further into this, it seems the CC2650 and CC2640 may support this feature. I have found the following E2E threads which provide some insight:

https://e2e.ti.com/support/wireless-connectivity/bluetooth-group/bluetooth/f/bluetooth-forum/536730/how-do-i-set-up-cc2650-8kb-cache-as-ram-using-iar

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/507034/how-to-use-cache-8k-to-ram-on-cc26xx

https://e2e.ti.com/support/wireless-connectivity/bluetooth-group/bluetooth/f/bluetooth-forum/413324/how-use-8kb-cache-on-cc2650

0 Vikas R J over 1 year ago in reply to Jan

Prodigy 70 points

Hi Jan,

thank you for thread links, finally i am able to configure Enable cache as GPRAM

Steps which i undertaken to enable cache as GPRAM

In ccfg.c file set flag to 0 in Enabling cache as GPRAM
In linker cc26xx_app.cmd file defined GPRAM origin and length in memory{}
Defined CACHE_AS_RAM in Predefined symbols in properties
Added .StaticBuffers and .GlobalBuffers into GPRAM section if CACHE_AS_RAM is enabled.
- example to add staticbuffers
- in cc26xx_app.cmd
- Memory allocation showing that buffers are inside GPRAM section
The following is set in main():
/* Keep cache powered during sleep */
Power_setConstraint(PowerCC26XX_SB_VIMS_CACHE_RETAIN);
Power_setConstraint(PowerCC26XX_NEED_FLASH_IN_IDLE);
Conclusion:
- SRAM consumption is 86% before adding GPRAM
- SRAM consumption is 69% after adding GPRAM since .StaticBuffers and .GlobalBuffers inside GPRAM section
  
  please let me know if anything is wrong or something i need to take care other than this

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CC2650: Missing Documentation for Configuring Cache as GPRAM in BLE SDK 2.02.08.12

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