Fuse Mirror Issue in MC33772B

[Sylvia_jiang]

Hi NXP Community,

          I am working with MC33772 Fuse Mirror. To update Fuse Mirror Data with my own value I read default value firstly when end of auto read after POR as below:

and then I set the 0Ch Fuse Mirror D0-D8 to 0 successfully as below procedures:

But I found that 02h Fuse Mirror value is not default  when I read back 02h Address  as sequence of read operations. Why ? Looking forward to your reply. 

BR

Sylvia

[JozefKozon]

Hi Sylvia,

please refer to a paragraph in the page 54. and to Figure 18. in the MC33772B datasheet. 

The mirror memory is automatically loaded from the Fuses Cell Array after each POR and if EEPROM is detected, then the mirror memory is loaded with content of the EEPROM.

Have you done POR after the write to the 0Ch Fuse Mirror register?

With Best Regards,

Jozef

[Sylvia_jiang]

Hi Jozef，

          Thanks for your reply!

          Our module is no external EEPROM connected with MC33772. 

          Have you done POR after the write to the 0Ch Fuse Mirror register?

                 ----> No

         detailed procedure is:

1. Config MC33772 after POR

2. Set FST=000 & FSTM=1 to switch "Low_Power_S state" to "Enable_SPI_Write_S" 

3. Set mirror register 0Ch bit0-bit8 to 0

4. Set FST=100 & FSTM=1 to return to "Low_Power_S state"

5. Read back mirror register 02h and found that value is not what has been automatically loaded from the Fuses Cell Array.

BR

Sylvia

[JozefKozon]

Hi Sylvia,

I apologize for a late reply. I have contacted an application engineer for an advice on this case. So far there is no answer from him. As soon as he answers me, I will definitely reply to you.

Thank you for your patience. 

With Best Regards,

Jozef

[JozefKozon]

Hi Sylvia,

there is still no answer from the application engineer. I have sent him a reminder. Hopefully he will answer me soon.

Thank you for your patience. 

With Best Regards,

Jozef

[Sylvia_jiang]

Hi Jozef，

         Could you provide an algorithm about ECC of customized value to get the correct values for DEC_ENCODE_LSB and DEC_ENCODE_MSB?

BR

Sylvia

[JozefKozon]

Hi Sylvia,

you can use the ECC encoder attached.

With Best Regards,

Jozef

[Sylvia_jiang]

Hi Jozef,

         Thanks for your help!

         May I get more details about Hamming code in this sheet?  for example what is meaning of ECC_group1/ECC_group2/ECC_group3/Backup1? What do the "din_max" and "dcin_max" stand for? What is the MATRIX7-MATRIX0? Is there any reference manual?

BR

Sylvia

[JozefKozon]

Hi Sylvia,

I have found a .pptx file and a python script attached. Please also refer to the section 9.12.1 in the MC33772C datasheet.

With Best Regards,

Jozef