TMS570LC4357: NOINIT Variables on RAM

Zonguldak's Rose <3

Part Number: TMS570LC4357
Other Parts Discussed in Thread: TMS570LS3137

Tool/software:

I want to use a part of ram as a nonvolatile memory like eeprom. I do not want to initialize or set to zero variables without poweron reset.I am trying this concept but avoiding ECC errors and to ensure integrity of RAM I want to use meminit fuction to all ram. I am trying to meminit to half part of RAM sections(total 8 hardware section, ı'm grouping this 8 hardware section as 2 software section each 4 hardware sections ) using MEMINITDOMAIN register and after that I'm copying my data to this section from section that has no initialization. I am using meminit function to initialize second half part of RAM. After initialization of second half part of RAM I'm copying again data from first part of the RAM to second part of the RAM and I'm using meminit function to initialize first part of RAM. (I'm also editing my linker file correctly)

In theory it seems like a legal way to use a part of ram as a noinit memory. But when I use this scenario I am to encounter a few problems.

When I software,cpu or system reset there is no problem also when I use PORRST(power on reset) button on HDK there is no problem. But when I tried turn HDK's power off and after that power on, the all RAM variables are garbage value. (I'm reconnecting to HDK with IDE after power off/power on sequence to see RAM variables). When I tried to use PORRST button again to see behaviour of broken RAM, the RAM variables seems normal after porst button. I'm running code again and this time I'm encountering ESM error on startup.

I'm attaching a file to clarify what I'm trying.

The ESM error that I see is ESM group 3 channel 8 error. When I look up to datasheet, it says this error is reserved so I can not analyze the error.
I think ECC logic causes of these problems.
1) Can I disable ECC logic when the code run on startup file ?
2) Why the behaviour of RAM different when I power off and PORRST button ?
3) How can I use a part of RAM as a NOINIT section correctly ? Is there a legal way to implement it ?
4) What means ESM group 3 channel 8 error ?

8 months ago

0 jagadish gundavarapu 8 months ago

TI__Guru 69761 points

Hi Rose,

First i am suggesting you to refer below threads to understand the behavior of RAM during RESET and power off.

(+) RM48 RAM status after Reset - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(+) TMS570LC4357: Halcogen - API to generate soft reset - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(+) TMS570 RAM state after nPORRST - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Zonguldak's Rose <3 said:
I want to use a part of ram as a nonvolatile memory like eeprom.

It may not be possible to use RAM as a nonvolatile memory.

--
Thanks & regards,
Jagadish.

0 Zonguldak's Rose <3 8 months ago in reply to jagadish gundavarapu

Prodigy 141 points

Hi Jagadish,

I read the threads that you mentioned. This threads explains RAM behaviour on different reset conditions. But my problems is not exactly related. I know that when the PORRST happens, I have to init or zero-init all the RAM properly.

Please read this thread to understand what I trying to do.

https://e2e.ti.com/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1077304/tms570lc4357-no-init-memory-on-reset-for-storing-reset-information

jagadish gundavarapu said:
It may not be possible to use RAM as a nonvolatile memory.

I know that it is not exactly a non-volatile memory, I just want to use some RAM variables as NOINIT variables like the thread I mentioned above.

I know if the PORRST happens, I can't use RAM variables but when CPU reset or software reset happens I dont't want init the variables and If it useful I want to use it.

I do it as exactly that the figure I attached image on the thread with using tms570ls3137.

Please read again my questions, If you don't understand I can explain it again. Can you answer my questions that I numbered (specially number 4)

0 jagadish gundavarapu 8 months ago in reply to Zonguldak's Rose <3

TI__Guru 69761 points

Hi,

I found one example project that prevent the part of the RAM to NOINIT.

(+) TMS570LC4357: No init memory on reset for storing reset information - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

It is tested and seems working as per the screenshots they shared.

Please have a look and download the project.

--
Thanks & regards,
Jagadish.

0 Zonguldak's Rose <3 7 months ago in reply to jagadish gundavarapu

Prodigy 141 points

Please read my questions. I sent the same link as you sent me. This is not an answer. I know it is working and I already tested it. I explained what is my purpose and what is the problems that I face.

0 jagadish gundavarapu 7 months ago in reply to Zonguldak's Rose <3

TI__Guru 69761 points

Hi,

Zonguldak's Rose <3 said:
4) What means ESM group 3 channel 8 error ?

I think it is not ESM group 3 channel 8 error, because it is reserved ESM channel:

Can you verify ESMSR3 value again, because if it is 0x8 means not the 8th channel.

If the value is 0x8 means, then the channel is 3rd channel because each bit in the register represents a channel from channel 0.

And it makes more sense if the error is channel 3, because channel 3 is uncorrectable RAM error.

This means the data present in the RAM and corresponding ECC sections are not matching.

Zonguldak's Rose <3 said:
2) Why the behaviour of RAM different when I power off and PORRST button ?

(8) TMS570 RAM state after nPORRST - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(8) RM57L843: EXTRST and PORST bits in SYSESR register - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

I think power off and PORRST have different behavior effect on RAM, as mentioned in above threads even for PORRST also the contents of the RAM will not get effect and only at on real power off condition the RAM will contain garbage values.

I am suspecting due to this behavior only we are getting ECC mismatches, and it leads to the ESM Group 3 channel 3 error.

--
Thanks & regards,
Jagadish.