BQ27421-G1: Default value for the DM_CODE

KWolfe

Part Number: BQ27421-G1

Hello,

I am currently utilizing the DM_Code as a versioning field for whether our BQ27421 has been programmed. I cannot find any documentation regarding this default value for this field, but am finding the factory devices reset the value to 49 (0x31) on power loss.

Can I rely on all future devices having the same default value or can you provide any other guidance on versioning schemes with respect to the BQ27421?

Thank you!

over 7 years ago

0 Onyx Ahiakwo over 7 years ago

TI__Guru* 76230 points

hi Kwolfe,
This gauge is a ROM based gauge, meaning that if there is a power loss,what ever has been configured gets wiped out. Your host needs to have non volatile memory that stores data configured on the gauge so in case of a power loss, it can get loaded back on the gauge. This info is covered in the quick start guide for the bq27421

www.ti.com/.../sluuah7

thanks
Onyx

0 KWolfe over 7 years ago in reply to Onyx Ahiakwo

Prodigy 40 points

Thanks,

I understand that - and we are doing all of that. But I need a way to detect when power loss occurs and would like to use the DM Code. There is presumably a default value for the DM Code. What is it?

0 KWolfe over 7 years ago in reply to KWolfe

Prodigy 40 points

For clarity, I am looking to check the DM Code in addition to the 'ITPOR' value.

0 Onyx Ahiakwo over 7 years ago in reply to KWolfe

TI__Guru* 76230 points

The default value is what ever it returns to in the event o f a power on reset. It doesn't change
thanks
Onyx

0 KWolfe over 7 years ago in reply to Onyx Ahiakwo

Prodigy 40 points

"It doesn't change"

Do you mean it doesn't change from device power on to device power on , or it will not change from chip to chip and revision to revision?

We are using this in production code that will be used across thousands of devices. I need to know the definitive behavior of this device.

0 Onyx Ahiakwo over 7 years ago in reply to KWolfe

TI__Guru* 76230 points

Kwolfe

going back to your original question, the itpor is what you need to detect power loss or if a POR has occurred..

All setting return to default values if a POR occurs. As long as the firmware versions are the same, default values are exactly the same
thanks
Onyx

Power management

Power management forum

BQ27421-G1: Default value for the DM_CODE