BQ25895: REG0C multi-read behavior

Mike Yu

Intellectual 2310 points

Part Number: BQ25895

Hi Team,

According to the DS, it seems that the customer can't use multi-read on REG0C.

Any idea what will be the result of REG0C if the customer used multi-read to read back all the registers after reset?

Will the device report from REG00 to REG14, but ignore REG0C register? Such as REG0B->REG0D->REG0E.

Or if the fault event is cleared when the EC read REG0C with the multi-read, the value of REG0C won't clear. Thus EC had to use single read to REG0C for the second time and the third time to clear the fault event.

Best regards,

Mike

over 4 years ago

0 Wyatt Keller over 4 years ago

TI__Guru** 105760 points

Hello Mike,

I think these questions were answered in your other thread: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1015610/bq25895-reset-bit-behavior/3755260#3755260

REG0C doesn't support multi-byte writes/reads.

Sincerely,

Wyatt Keller

0 Mike Yu over 4 years ago in reply to Wyatt Keller

TI__Intellectual 2310 points

Hi Keller,

Get it, so just want to double confirm that if the customer using multi read/write, the device won't report the data of REG0C, right? Thank you.

Best regards,

Mike

0 Mike Yu over 4 years ago in reply to Mike Yu

TI__Intellectual 2310 points

Hi Keller,

One more question for the customer, if the device will report the data of REG0C when using multi read/write, will the device report REG0C value as 0? Because REG0C didn't support multi read/write. Than kyou.

Best regards,

Mike

+1 Wyatt Keller over 4 years ago in reply to Mike Yu

TI__Guru** 105760 points

Hello Mike,

It should not report it as 0, you can reference the datasheet:

REG0C is a fault register. It keeps all the fault information from last read until the host issues a new read. For example, if Charge Safety Timer Expiration fault occurs but recovers later, the fault register REG0C reports the fault when it is read the first time, but returns to normal when it is read the second time. In order to get the fault information at present, the host has to read REG0C for the second time. The only exception is NTC_FAULT which always reports the actual condition on the TS pin. In addition, REG0C does not support multi-read and multi-write.

It needs to be read multiple times in order for the fault to be read and understood correctly.

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ25895: REG0C multi-read behavior