BQ27500_08 Datasheet, PDF (29/39 Pages) Texas Instruments – System-Side Impedance Track™ Fuel Gauge

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bq27500
bq27501
System-Side Impedance Track™ Fuel Gauge
SLUS785D – SEPTEMBER 2007 – REVISED APRIL 2008
It is important that BAT_GD be set to disable status (no battery charging/discharging). This prevents a
charger application from inadvertently charging the battery before an OCV reading can be taken. It is the
system’s responsibility to wake the bq27500/1 after it has gone into HIBERNATE mode. After waking, the
gauge can proceed with the initialization of the battery information (OCV, profile selection, etc.)
5.8 POWER CONTROL
5.8.1 RESET FUNCTIONS
When the bq27500/1 detects software reset ([RESET] bit of Control( ) initiated), it determines the type of
reset and increments the corresponding counter. This information is accessible by issuing the command
Control( ) function with the RESET_DATA subcommand.
As shown in Figure 5-3, if a partial reset was detected, a RAM checksum is generated and compared
against the previously stored checksum. If the checksum values do not match, the RAM is reinitialized (a
Full Reset). The stored checksum is updated every time RAM is altered.
DEVICE RESET
Generate Active
RAM checksum
value
Stored
checksum
NORMAL
OPERATION
NO
Do the Checksum
Values Match?
YES
Active RAM
NO
changed ?
YES
Store
checksum
Generate New
checksum value
Re-initialize all
RAM
Figure 5-3. Partial Reset Flow Diagram
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FUNCTIONAL DESCRIPTION
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