LP87745-Q1: AWR2944: LP8774x CRC Support

Hi John,

LP8774x-Q1 supports SPI communication with CRC which can be enabled in the device via SPI_CRC_EN bit. The software application needs to calculate the CRC required by the device.  You can refer to the 7.5.1.2 Serial Peripheral Interface (SPI) section of data sheet for detailed description. 

You can also refer to the following CRC related question. 

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1344230/lp87745-q1-spi-crc-calaculation 

If you do not have full datasheet , you can request one by referring to following FAQ. 

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1183634/faq-lp87745-q1-where-can-i-find-functional-safety-documents-and-full-data-sheet 

BR,

Ishtiaque 

Hello Ishtiaque Panhwar,

Thanks for response.

-->Can you let us know below points:

                                     * Since awr2e44 Mcu is available in Little Endian platform. LP8774 Pmic chip is available in Little Endian or Big Endian ?

                                     * Can you also let us know If LP8774 is available in Big Endian and our Mcu is in Little Endian Platform kindly share configurations and challenges. I will be waiting for your valuable response and Support.

--> Im unable to access the site for requesting full data sheet. Kindly can you let me know regarding this.

Thanks & Regards,

Vicky John T

Hi John,

vicky john T said:

           * Since awr2e44 Mcu is available in Little Endian platform. LP8774 Pmic chip is available in Little Endian or Big Endian ?

The use a standard CRC-8 polynomial to calculate the checksum value: X8 + X2 + X + 1.The CRC algorithm details are as follows:
• Initial value for the remainder is all 1s.
• Big-endian bit stream order

vicky john T said:

--> Im unable to access the site for requesting full data sheet. Kindly can you let me know regarding this.

Sorry for that there might some IT related technical issue. Meanwhile you can use below link to request access. 

https://www.ti.com/drr/opn/LP8774X-Q1DOCUMENTS

BR,

Ishtiaque 

Hello Ishtiaque Panhwar,

Thank you for the reply.

Big-endian bit stream order:

            * Can i confirm that PMIC chip available in BiG Endian. Because our Team would like to know if Mcu available in Little Indian Platform and PMIC available in Big Endian Platform any specific configurations are required. Kindly can you confirm regarding this

Thanks & Regards,

Vicky John T

Hi John,

In my previous reply, I have described that PMIC CRC algorithm is Big-endian. I am not sure about MCU since I am only support engineer for PMIC. 

You can enquiry regarding MCU making another thread but make sure you mention AWR2944 part name in the thread not PMIC number otherwise it would come to me again.

Br,

Ishtiaque 

Hello Ishtiaque Panhwarm,

                    For developing Autosar MCAL we took Ti support, They confirmed us that MCU is available in Little Endian. They asked us to reach you regarding this issue

Thanks & Regards,

Vicky John T

Hi John,

Alright if you know already then that is good but if you want to confirm it again then you can do so by making another thread to AWR team. 

But with regards to LP8774x-Q1, is your question now answered? let me know then we can close the thread. 

BR, 

Ishtiaque 

Hello Ishtiaque Panhwar,

We have tried reading MANUFACTURING_VER and few read access registers from PMIC chip, But im getting response 0x12ED. 

I also referred below link for transmitting command and address for reading registers. 

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1117230/lp87745-q1-sample-code-for-reading-and-writing-data-into-pmic

* Please kindly share any basic Mcal example for reading/ writing into PMIC chip. Mcal loop back example works fine. Due to lack of test points we are unable to probe the clock and data lines

Thanks & Regards,

Vicky John T

Hi Vicky,

Sorry for  the delay in response. 

vicky john T said:

MANUFACTURING_VER

Why are you reading that register at first place. Try to read something like DEV_REV, NVM_CODE_1 or NVM_CODE_2.

vicky john T said:

e2e.ti.com/.../quote]

So the example code is provided in that E2E thread. Didn't that workout for you?

I have another sample code in C but I am sharing through email. I hope that solves your issue.

BR,

Ishtiaque