BQ78350-R1: Description of some of the registers

Thank you Matt,

So this flag will be written when PF SAFE flags conditions to blow the fuse are valid, regardless if the actual fuse (through the SAFE pin activation) was blown or not?

I am asking this because to blow the safety fuse there is an additional condition on the cell voltages before the device activates the SAFE pin.

Thanks,

Alaa

Hi Matt,

The more important condition to me was the low voltage condition.

In the reference manual the voltage limit is 3.5V, I initial thought it is per cell but apparently this is the total voltage of the pack. (it is hard to think initially that this value is meant for the pack voltage, at this level many things will be tripped before the cell voltages reach that level even with a 3 cells pack, I am also not sure if the AFE bq769x0 would be operating as it is supposed to, the minimum recommended operational voltage in the datasheet is 6V, I could not find a reference for operating above 3.5V for the companion chip)

So assuming BQ78350-R1 with the AFE BQ769x0 are both operating at a 3.4V pack voltage then the SAFE pin will not activate and the Fuse Flag will not be written?

Thanks,

Alaa

I would like to jump to the next 2 registers in the PF Status memory, it is the Operation Status A and Operation Status B.

Those 2 registers are described within the Battery Management Studio ( I am using version 1.3.54) but this description does not line up with description in the reference manual.

I am attaching pictures below : (last one is a description of the OperationStatus() from Reference Manual with my highlights)

Besides the fact that the least significant bytes in the Battery Management Studio are aligned with the MSB of the OperationStatus in the RM (crisscross), there is those 3 bits that I circled in red which do not match the description shown in the Battery Management Studio.

Can you provide more clarification regarding this?

Thanks,

Alaa

Hi Alaa,

I just opened this in BQStudio and I do not observe the same thing - my Operation Status registers match the documentation.

It may be possible that an older version of the BQ78350-R1 settings file (.bqz file) is included with this older revision of BQStudio. I am using the latest version v1.3.92. BQStudio was recently updated on ti.com - I recommend downloading the latest version or at the very minimum the production version v1.3.86.

The 'BQSTUDIOTEST' version is generally best to use, but it labeled as TEST and disclaimers are added because it has not been in use for a very long time. 

Best regards,

Matt

Hi Matt,

I tried Version 1.3.86 and also 1.3.92.

Using either versions I still see the same data for Operation Status A or B. (I had an issue installing BQStudio versions on top of each others, better to uninstall using windows the older version then manually delete to remaining folder and files before installing the newer version)

Can you please share with me your .bqz file for the BQ78350-R1 ? or unless you recommend something else to try?

Thanks,

Alaa

Hi Alaa,

The latest version of the bqz can be downloaded from the product folder here: http://www.ti.com/product/BQ78350-R1/toolssoftware under the link 'bq78350-R1 Device Firmware'

Once you download the zip file, copy the bqz file to this directory: C:\ti\BatteryManagementStudio\config\

I think this should resolve the issue. I am also attaching a copy of the bqz.

Best regards,

Matt2275.1E9B_1_03-bq78350_R1.bqz

Hi Matt,

I am not sure what would be different on my PC.

I copied the .bqz version you included in the previous post into the \config\ folder, it did not fix what I am seeing in the battery management studio.

I tried and downloaded the bq78350R1 Firmware Bundle but this was for the firmware version 1.04, the devices I am using are 1.03.

Any additional idea to resolve this ?

Thanks,

Alaa

Hi Alaa,

I figured out the issue. I was looking at the Operation Status on the Registers screen and I think you were looking at the Operation Status in Data Memory. When I look at this parameter in Data Memory, I see the same thing as you. 

The bits displayed by BQStudio are defined by the .bqz file. It appears that the bqz has these bits set to hidden for some reason when they should be visible. I will notify our firmware team to see if we can update this in the next update of BQStudio.

Sorry about the confusion,

Matt

Hi Matt,

Great that you can see what I am seeing!

Can you please confirm if I need to read the hex value of the operation Status A/B (in PF Status Data Memory) following the datasheet description of the bits (and how the operation Status A/B show up under the Registers tab) and ignore those labels that show up when you press on the field in question under the Data Memory?

Thanks,

Alaa

Hi Alaa,

Confirmed. The 'RSVD' are only labels that come from the bqz file.

Thanks and sorry for the confusion,

Matt

Hi Matt,

One more clarification, I am inserting the bit order for Operation Status from the reference manual:

Bit 6 in Operation Status is RSVD (as shown above) while in Data Memory (DM) the Operation Status A MSB bit 6 is SMOOTH, I will assume it is supposed to be RSVD in DM because in RM the word SMOOTH does not exist. Also DSG and CHG bits are flipped around in the Battery Management Studio Data Memory - PF Status, should I assume the correct representation is in the picture above?

Also how about the fact that the byte mapping is crisscross?

So as an actual example if I have a value of 0x0175 in the Operation Status A (Data Memory - PF Status) should I read it as follows:

SEC0 (bit8),  RSVD(bit6), SAFE(bit5), HCFET(bit4),  DSG(bit2), PRES(bit0)?

or should I take what the Battery Management studio is showing me:

Thanks,

Alaa

Hi Matt,

Thank you for your clarification.

on a slightly different topic I would like to point out to some potential typos that I found in the reference manual, I am inserting marked up snapshots below:

Thanks,

Alaa

Great, thank you Alaa. I will add these to the list of planned fixes to the reference manual. I expect to release a revision later this summer.

Best regards,

Matt