TJA1128

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TJA1128

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cipriansalagean
Contributor II

Hi,

I'm working with TJA1128 LIN mini system basis chip.

The setup is:

- S32K144EVB running NXP example for TJA1128 SBC

- custom board with TJA1128: this board contains only the chip no other components, it is placed on a breadboard and wires are connected to S32K144EVB. It is more a breakout board.

The TJA chip is in CONFIG mode. At start the MCU is writing the configuration registers of the TJA - see attached picture. The last register written is the CRC register with 0x91 (value checked also with NXP CRC calculator for this chip).

The problem is that after the CRC register is written the SBC does not Restart (CRC is correct normally) to confirm the end of CONFIGURATION sequence.

The Reset pin is High (as can be seen in picture). So the chip remains in CONFIG mode.

Reading again the register at address 31h shows NVERR  active (The error status bit NVERR indicates whether a MTPNVM fault was detected). I NEED TO CONFIRM THIS.

If anyone has an idea what I'm doing wrong? Thanks in advance.

Could be because there are no capacitors on TJA breakout board board ?

Link to TJA1128 data sheet

https://www.nxp.com/docs/en/data-sheet/TJA1128-DS.pdf 

Config_09112018.PNG

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cipriansalagean
Contributor II

CRC value was wrong. Initial value for CRC calculation was not correct.

In NXP example was used TJA1128G and I have TJA1128E - initial values for CRC calculation is different. The values can be found in datasheet. 

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samchin
Contributor I

Regarding TJA1128 SPI Reading, Would it be available to tell how to do that? I didn't find that in the datasheet.  
Aside to CRC Value, the address value is 0x60h but I find the address of MTPNV CRC should be 0x30h in the datasheet, is there any explanation for that?  Thanks 

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cipriansalagean
Contributor II

Hi Sam,

 MTPNV CRC adress IS 0x30h but be careful because the address is on high 7 bits sent on SPI, R0 bit is for Read/Write. So it is

0x30 << 1 = 0x60: register address left shifted by one position.

pastedImage_1.png

There is an SDK and example how to use the SDK. Example runs on TJA1128  evaluation board from NXP,

Evaluation Board for TJA1128 LIN mini.

Link https://www.nxp.com/design/development-boards/analog-toolbox/evaluation-board-for-tja1128-lin-mini-s... https://www.nxp.com/design/development-boards/analog-toolbox/evaluation-board-for-tja1128-lin-mini-s...

To calculate the CRC after you change the TJA register use TJA1128_CRC_Calculator.xlsm

Hope this helps and is not too late

 

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