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PFD1, PFD0 in BQ20Z75

Hello there,

Just another quick post to mention more mismatching BQ20Z75 documentation. Luckily posts elsewhere indicated where the information can be found.

I have been trying to set up  BQEASY to calibrate and get a golden file for the BQ20Z75 (This is a misnomer, it really should be called BQVIRTUALLYIMPOSSIBLEFORNEWBIES (BQVIFN)but that's another story) and when I managed to get the DFI file I ran through and checked it.

One of the odd things was bit 6 of CFGB was set, but SLUU265A does not mention this bit. GGEV software however pops it up when you hover the mouse over the register in the SBS screen and gives it and its left hand colleague mnemonics of PFD1 and PFD0. The forum indicated information on these bits relate to the PFD display in relation to the LEDS, but the BQ20Z75 doesn't have any.

The questions of TI are:

1. Why does BQEASY set this bit, even when the number of leds is set to 0.

2. Why does BQEASY even mention them on the SBS screen for this chip when  the but the documentation doesn't.

3. Most importantly, do we care what these bits are set to anyway, or should I manually go set PFD0 to a 0 anyway.

The conclusion I come to is that this is a niggly little bit of BQVIFN that probably got missed by TI's extensive verification and validation processes, and I should stop whinging and go set it to 0 anyway.

Regards

Simon Buchwald

PS I probably wouldn't ever have noticed PFD0 if the bit hadn't been set!

  • Simon,

    The PFD0 and PFD1 flags do not apply to the bq20z75, since it does not support LED drive as you noted. These flags should not show up when you select the Operation Cfg B register on the Data Flash screen, so this must have been an oversight. I did test the bqEASY tool and these bits did not get set when I ran through the process. Anyway, they get ignored by the firmware.

    Best regards

    Tom

  • Hi Tom,

    Thanks for confirming my supposition there, PFD0 definitely gets set in my setup, even though I select zero LEDS, I have just set the bit to zero to be on the safe side!

    Cheers

    Simon Buchwald