IWR6843: Disabling L3 RAM Memory Initialization

Curtis Belknap

Part Number: IWR6843

Hello,

I am attempting to set a small portion of L3 RAM with a know test pattern but the memory in question is alway filled with zeros when I read back the pattern.
After consulting the reference manual I discovered the following section (SWRU522E pg 1553):

10.3.2 Memory Auto-Initialization

Hardware auto-initialization of the DSS_L3 memory banks is supported at reset, so that false ECC failures
are not reported by writing to the MSS_TOPRCM.MEMINITSTARTSHMEM register. Memory initialization
is provided for each bank of 128KB. The memory is initialized to all zero values, and for every 32-bit word
calculated, ECC is 0x0C. Memory initialization status is available in the
MSS_TOPRCM.MEMINITDONESHMEM register.

Is there any way to disable the automatic memory initialization?

- Curtis

over 4 years ago

0 Nitin Sakhuja over 4 years ago

TI__Mastermind 30405 points

Hi Curtis,

As mentioned in the following thread, the bootloader initializes the TCMA and TCMB before passing control to the application. However, I need to check with our bootloader team if this initialization applies to the L3SRAM as well and if there are any ways to disable it for specific memory regions (e.g. using linker command file techniques).

https://e2e.ti.com/support/sensors/f/1023/p/866157/3210491

Please allow me a couple of days to check on this.

Regards

-Nitin

0 Nitin Sakhuja over 4 years ago in reply to Nitin Sakhuja

TI__Mastermind 30405 points

Hi Curtis,

Setting up L3 RAM memory pattern is independent of bootloader memory initialization. Even if bootloader initializes L3RAM, it would be set to all zeros and later the application can set it to a known pattern.

1. Could you please clarify how and when are you setting up the memory pattern in the application flow?

2. Are you trying to set the pattern from the MSS or DSS?

Regards

-Nitin

0 Curtis Belknap over 4 years ago in reply to Nitin Sakhuja

Intellectual 420 points

1. Could you please clarify how and when are you setting up the memory pattern in the application flow?

I have a statically allocated array that is positioned in a copy section that aliases the first 128[B] of L3 memory. This array reads all zeros regardless of the initialized value.

2. Are you trying to set the pattern from the MSS or DSS?

I am setting the pattern from the DSS.

-- Curtis

0 Nitin Sakhuja over 4 years ago in reply to Curtis Belknap

TI__Mastermind 30405 points

Hi Curtis,

Please provide your linker command files for DSS and MSS both.

Regards

-Nitin

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IWR6843: Disabling L3 RAM Memory Initialization