BQ27505 Datasheet, PDF (20/42 Pages) Texas Instruments – System-Side Impedance Track™ Fuel Gauge

bq27505
Not Recommended for New Designs
SLUS884 – FEBRUARY 2009
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4.3 MANUFACTURER INFORMATION BLOCKS
The bq27505 contains 96 bytes of user programmable data flash storage: Manufacturer Info Block A,
and Manufacturer Info Block B. The method for accessing these memory locations is slightly different,
depending on whether the device is in UNSEALED or SEALED modes.
When in UNSEALED mode and when and 0x00 has been written to BlockDataControl( ), accessing the
manufacturer information blocks is identical to accessing general data flash locations. First, a
DataFlashClass( ) command is used to set the subclass, then a DataFlashBlock( ) command sets the
offset for the first data flash address within the subclass. The BlockData( ) command codes contain the
referenced data flash data. When writing the data flash, a checksum is expected to be received by
BlockDataChecksum( ). Only when the checksum is received and verified is the data actually written to
data flash.
As an example, the data flash location for Manufacturer Info Block B is defined as having a Subclass =
58 and an Offset = 32 through 63 (32 byte block). The specification of Class = System Data is not needed
to address Manufacturer Info Block B, but is used instead for grouping purposes when viewing data
flash info in the bq27505 evaluation software.
When in SEALED mode or when 0x01 BlockDataControl( ) does not contain 0x00, data flash is no longer
available in the manner used in UNSEALED mode. Rather than issuing subclass information, a
designated Manufacturer Information Block is selected with the DataFlashBlock( ) command. Issuing a
0x01 or 0x02 with this command causes the corresponding information block (A or B, respectively) to be
transferred to the command space 0x40…0x5f for editing or reading by the system. Upon successful
writing of checksum information to BlockDataChecksum( ), the modified block is returned to data flash.
Note: Manufacturer Info Block A is read-only when in SEALED mode.
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GENERAL DESCRIPTION
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