BQ28Z560-R1_14 Datasheet, PDF (36/61 Pages) Texas Instruments – Single Cell Li-Ion Battery Gas Gauge

bq28z560-R1
Not Recommended For New Designs
SLUSBD3 – APRIL 2013
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The Lifetime Data logging function helps development and diagnosis with the bq28z560-R1. The bq28z560-R1
device logs the Lifetime Data as specified in the Lifetime Data and Lifetime Temp Samples data flash
subclasses. The data log recordings are controlled by the Lifetime Resolution data flash subclass.
The Lifetime Data Logging can be started by setting the IT_ENABLE bit and setting the Update Time register to a
non-zero value.
Once the Lifetime Data Logging function is enabled, the measured values are compared to what is already
stored in the data flash. If the measured value is higher than the maximum or lower than the minimum value
stored in the data flash by more than the Resolution set for at least one parameter, the entire data flash Lifetime
registers are updated after at least LTUpdateTime.
LTUpdateTime sets the minimum update time between DF writes. When a new max/min is detected, an LT
Update window of 60 seconds is enabled and the DF writes occur at the end of this window. Any additional
max/min value detected within this window will also be updated. The first new max/min value detected after this
window will trigger the next LT Update window.
Internal to bq28z560-R1 is a RAM max/min table in addition to the DF max/min table. The RAM table is updated
independent of the resolution parameters. The DF table is updated only if at least one of the RAM parameters
exceeds the DF value by more than the resolution associated with it. When DF is updated, the entire RAM table
is written to DF. Consequently, it is possible to see a new max/min value for a certain parameter even if the
value of this parameter never exceeds the maximum or minimum value stored in the data flash for this parameter
value by the resolution amount.
The Lifetime Data Logging of one or more parameters can be reset or restarted by writing new default (or
starting) values to the corresponding data flash registers through sealed or unsealed access as described below.
However, when using unsealed access, new values will only take effect after device reset.
The logged data can be accessed as R/W in UNSEALED mode from the Lifetime Data SubClass (SubClass
ID=59) of data flash. Lifetime Data may be accessed (R/W) when sealed using a process identical in
Manufacturer Info Block B and C. The DataFlashBlock command code is 4.
NOTE
Only the first 32 bytes of Lifetime Data (not resolution parameters) can be R/W when
sealed. See MANUFACTURER INFORMATION BLOCKS for sealed access.
The logging settings such as Temperature Resolution, Voltage Resolution, Current Resolution, and Update Time
can be configured only in UNSEALED mode by writing to the Lifetime Resolution subclass (SubClassID=66) of
the data flash.
The Lifetime resolution registers contain the parameters that set the limits related to how much a data parameter
must exceed the previously logged Max/Min value to be updated in the lifetime log. For example, V must exceed
MaxV by more than Voltage Resolution to update MaxV in the data flash.
DETAILED CONFIGURATION REGISTER DESCRIPTIONS
The Pack Configuration Register
Some bq28z560-R1 pins are configured via the Pack Configuration data flash register, as indicated in Table 15.
This register is programmed/read via the methods described in ACCESSING THE DATA FLASH. The register is
located at subclass = 64, offset = 0.
High Byte
Low Byte
Bit 7
RESCAP
GNDSEL
Table 15. Pack Configuration Bit Definition
Bit 6
CalEn
RESFACTSTEP
Bit 5
RSVD
SLEEP
Bit 4
RSVD
RMFCC
Bit 3
RSVD
CLR_READ
Bit 2
IWAKE
ALRT_POL
Bit 1
RSNS1
RSVD
Bit 0
RSNS0
TEMPS
36
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