BQ2019PW Datasheet, PDF (21/27 Pages) Texas Instruments – ADVANCED BATTERY MONITORIC

bq2019
ADVANCED BATTERY MONITOR IC
SLUS465E – DECEMBER 1999 – REVISED FEBRUARY 2003
ERRATA
Issue : This errata ONLY applies if page 1 (address 0x20– 0x3F) or page 2 (address 0x40– 0x5F) of the
embedded flash memory is read through the HDQ interface. If your specific application or method of use
does not involve reading from any location on page 1 or page 2 of flash memory, please disregard this
erratum.
Description:
This errata ONLY applies if page 1 (address 0x20– 0x3F) or page 2 (address 0x40– 0x5F) of flash memory is
read through the HDQ interface. Under rare conditions, the read operation may return 0xFF data for locations
on page 1 or page 2. However, this is only an issue with the READ operation. There is no impact on the content
or the integrity of the data stored in page 1 or page 2 of the flash memory.
This document also describes two simple methods of safeguarding against this condition. Both methods are
implemented on the host system software. No hardware modifications are required.
Safeguarding Method Number One:
This method ONLY applies if the user does not ever write to any location on page 0 (0x00–0x1F). This method
uses a flash to RAM transfer sequence in order to clear any potential read issues.
Accessing page 1 or
page 2
Did you read data 0xFF
from a location on
page 1 or page 2?
No
Proceed. No action
required.
Yes
Write data 0x48 to
address 0x62
(FCMD=0x48)
Read desired address in page 1 or
page 2. Data is valid.
Figure 1. Procedure Flow for Safeguarding Method Number One
Safeguarding Method Number One:
For all applications that write to page 0, please proceed to Safeguarding Method Number Two.
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