TMS320F28027: Calibration Data Checksum

Sam Chen79

Part Number: TMS320F28027

Hi,

We have a need to calculate the checksum of the Calibration Data (Device_cal function, TMS320F28027 memory map address range 0x3D7C80 to 0x3D7CBF). What we noticed is that if we calculate the checksum of this address range, it varies from part to part.

To my understanding, this address range consists of the the configuration data parts and the code parts (that copy the configuration data from OTP ROM to the respective registers).

Which part of this address range does not vary from part to part? And, what is the address range of the code parts?

Thank you in advance for your help.

over 4 years ago

0 Hareesh Janakiraman over 4 years ago

TI__Guru* 95315 points

The section you refer to will contain both code and calibration data (which will vary from one part to another). Hence a checksum is not practical.

0 Sam Chen79 over 4 years ago

Intellectual 390 points

Hi Hareesh,

Thank you for your reply.

Would it be possible to disassemble the Device_cal() section to determine which areas are the executable instructions and which areas are the calibration data?

Additionally, will the executable instructions in this section vary from one part to another?

Thank you,

Sam

0 Hareesh Janakiraman over 4 years ago

TI__Guru* 95315 points

Sam Chen79 said:
Would it be possible to disassemble the Device_cal() section to determine which parts are the executable instructions and which areas are the calibration data?

Sam,

There are just a handful of locations that are static, so I am skeptical if a checksum is going to be effective.

Sam Chen79 said:
does the executable instructions in this section vary from one part to another?

No.

0 Sam Chen79 over 4 years ago in reply to Hareesh Janakiraman

Intellectual 390 points

Hi Hareesh,

What are the address ranges of the executable instructions in the section? We would like to explore the possibility of calculating the checksum of these locations.

Thank you,

Sam

+1 Hareesh Janakiraman over 4 years ago in reply to Sam Chen79

TI__Guru* 95315 points

Sam,

As mentioned before, there is not a contiguous section of code. The calibration data is interspersed with code. Locations 0x3D7C80 through 0x3D7C92 are static, with the exception of the following locations:0x3D7C83, 0x3D7C85, 0x3D7C8D, 0x3D7C8F, 0x3D7C91.

0 Sam Chen79 over 4 years ago in reply to Hareesh Janakiraman

Intellectual 390 points

Hareesh,

Thank you for providing the address ranges.

I did a brief test and found that only location 0x3D7C90 and 0x3D7C92 are static and the rest of the locations between locations 0x3D7C80 and 0x3D7C92 vary part to part.

Can you please confirm the address ranges again for the TMS320F28027FPTT ?

Thank you,

Sam

0 Hareesh Janakiraman over 4 years ago in reply to Sam Chen79

TI__Guru* 95315 points

Sam,

could you dump the contents of a few devices for addresses 3D7C80 through 3D7C92 and share it with me?

0 Sam Chen79 over 4 years ago in reply to Hareesh Janakiraman

Intellectual 390 points

Hareesh,

I dumped the contents of three devices for addresses 3D7C80 through 3D7C92 and the static areas are exactly what you mentioned. There was an issue calculating the incorrect addresses but after fixing that these devices now have the same checksum among them.

Thank you for your help!

Sam

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TMS320F28027: Calibration Data Checksum