TMS570LC4357: OTP Memory Map Problem of not Being able to Access a Part of OTP Domain

Ktmn

Part Number: TMS570LC4357
Other Parts Discussed in Thread: UNIFLASH, HALCOGEN

I am using this processor and i have a problem with OTP memory space.

In the processor manual, the Customer-OTP field consists of 3 Banks.

Actual sizes of Bank0 and Bank1 appear to be 4KB. But when I check these Banks from memory map or Uniflash on the IDE, the fields after 3KB are replaced by "?????" instead of "FFFFF". it seems.

And when I hover over it, I see a warning like "target can not read the device".

The visible area in both benches is 3Kb.

Can you tell me why the next 1 KB is showing as a question mark, why we can't access it and how can I access it?

Thanks & regards.

over 2 years ago

+1 jagadish gundavarapu over 2 years ago

TI__Guru 70241 points

Hi Ktmn,

The MPU settings for the project you are using may not be configured well.

For example, here is the default HALCoGen project MPU settings at starting of OTP regions.

Here you could see the 8MB region is enabled from the starting address of 0xF0000000, which is customer OTP region starting address.

And now you could see the memory browser for this project at customer OTP regions.

Now you could see the customer OTP region for Bank0 is extended till 0xF0000FFF, which is nothing but a 4KB.

Similarly, you could see the Bank-1 customer OTP region is extended from 0xF0002000 to the 0xF0002FFF. That is 4KB again.

So, i am attaching this test project for your reference please do test with this project.

Customer_OTP_Range_TEST_LC4357.zip

Thanks & regards,
Jagadish.

0 Ktmn over 2 years ago in reply to jagadish gundavarapu

Prodigy 120 points

Thank you, this resolved my issue completlely. I want to ask two more question with using your images.

1) In your memory map, otp area is not fully pure. When I look at my memory map, it is not also pure. But ı think it must be pure.

Why are there certain corruptions in the otp domain? Why isn't the whole field "FFFFFFFF".

2) According to proccessor manual, We can set the 1s in the otp field to 0, but not the 0s. I wonder if I can set the logic-1 bits in the corrupted areas to 0? If I can do that, isn't it against the "non-rewritable" logic of OTP?

+1 jagadish gundavarapu over 2 years ago in reply to Ktmn

TI__Guru 70241 points

Hi Ktmn,

It is due to the ECC correction.

On this device the ECC is enabled by default, so due to that a single bit correction will happen. I mean after the manufacturing both OTP memory region and OTP ECC region are containing all FF's but this leads to the mismatch of data and ECC, so there will be a single bit error corrections can happen due to that the OTP region will not contain all FF's.

But once you program with required data then you can't see these corrected single bit errors as ECC memory will get program with right bits.

To understand this behavior, please refer below threads:
(+) TMS570LS1224: Reading OTP with Uniflash v3.4.0 - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(+) [FAQ] TMS570LC4357: After erasing, the flash contents should become 0xFFFFFFFF. Why the flash content in CCS memory browser is not 0xFFFFFFFF? - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(+) TMS570LC4357: Example code for F021 Flash API - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Thanks & regards,
Jagadish.