ZHCSAB6E October 2012 – May 2018 BQ27545-G1
PRODUCTION DATA.
The Lifetime Data logging function helps development and diagnosis with the bq27545-G1. IT_ENABLE must be enabled (Command 0x0021) for lifetime data logging functions to be active. bq27545-G1 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 maximum or minimum is detected, a LT Update window of [update time] second 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 maximum or minimum value detected after this window will trigger the next LT Update window.
Internal to bq27545-G1, there exists a RAM maximum or minimum table in addition to the DF maximum or minimum 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 resolution associated with it. When DF is updated, the entire RAM table is written to DF. Consequently, it is possible to see a new maximum or minimum 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 Life Time 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 Lifetime Data Subclass (Subclass ID = 59) of data flash. Lifetime data may be accessed (R/W) when sealed using a process identical Manufacturer Info Block B. 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 maximum or minimum 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.