DS90UB964-Q1: can't access 964 i2c, why?

taotao wang

Prodigy 190 points

Part Number: DS90UB964-Q1

Hi team,

We are debugging our 964 board, but the MPU cann't access the i2c, and i2cdetect can't find 964 chip.

below are the related 964 power supply situmation. and the pdb is pulled up to vdd1v8 by 10K resistor,

please give me some advice about this issue.

13pin vddl_1v1 1.092v

44pin vddl_1v1 1.093v

21pin vdd_csi0 1.094v

33pin vdd_csi1 1.094v

52pin VDD_fpd1 1.093v

61pin VDD_fpd2 1.094v

48pin VDD18_p0 1.772v

47pin VDD18_p1 1.772v

1pin VDD18_p3 1.771v

2pin VDD18_p2 1.771v

32pin VDD18A 1.771V

49PIN VDD18_fpd0 1.767v

55PN VDD18_fpd1 1.767v

58PIN VDD18_fpd2 1.767v

64PIN VDD18_fpd3 1.767v

16pin VDDID 3.27V

46PIN IDX 1.767V

3PIN PDB 2.64V

45PIN MODE 1.771V

4PIN TESTEN 1.473V

Thanks & Best Regards

TaoTao Wang

over 6 years ago

0 Casey McCrea over 6 years ago

TI__Guru** 103215 points

Hello Taotao,

One quick item I see is that the TESTEN pin is pulled high. Please ensure this pin is tied to GND as per the datasheet recommendation.

Best Regards,

Casey

0 taotao wang over 6 years ago in reply to Casey McCrea

Prodigy 190 points

Hi Casey,

Thanks for your quickly response , I tied the TESTEN pin to GND. But the chip still can't be detected in I2C.

I alse tried to pull the PDB to gnd for a while when the system power on, and then release to high level, but the rsult hasn't changed.

Any other sugguestion?

Best Regards,

TaoTao Wang

0 Casey McCrea over 6 years ago in reply to taotao wang

TI__Guru** 103215 points

Hello TaoTao,

Can you please share a schematic for the device so that I can more easily check the connections?

Thanks,

Casey

0 taotao wang over 6 years ago in reply to Casey McCrea

Prodigy 190 points

Hi Casey,

Many thanks for your support, this issue has been resolved, the root cause is the i2c bus has been pulled by other chips.

Best Regards,

TaoTao Wang

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DS90UB964-Q1: can't access 964 i2c, why?