Required for WIN8 OS, the battery trip point (BTP) feature indicates when the RSOC of a battery pack has depleted to a certain value set in a DF register.
The BTP feature allows a host to program two
capacity or
state-of-charge–based
thresholds that govern the triggering of a BTP interrupt on the BTP_INT pin and the setting
or clearing of the OperationStatus()[BTP_INT] on the basis of
RemainingCapacity() or RelativeStateofCharge(). The interrupt is enabled or
disabled via Settings.Configuration.IO Config[BTP_EN]. Similarly, the polarity
of the interrupt is configurable based on the value set in Settings.Configuration.IO
Config[BTP_POL].
- OperationStatus()[BTP_INT] is set when:
- If Settings.Configuration.IO Config[BTP_MODE]is set to 0:
- Current > 0 and RemCap > “clear” threshold (“charge set threshold”). This threshold is initialized at reset from Settings.BTP.Init Charge Set.
- Current ≤ 0 and RemCap < “set” threshold (“discharge set threshold”). This threshold is initialized at reset from Settings.BTP.Init Discharge Set.
-
- If Settings.Configuration.IO Config[BTP_MODE] is set to 1:
- Current > 0 and RelativeStateofCharge() > “clear” threshold (“charge SOC set threshold”). This threshold is initialized at reset from Settings.BTP.Init Charge Set.
- Current ≤ 0 and RelativeStateofCharge() < “set” threshold (“discharge SOC set threshold”). This threshold is initialized at reset from Settings.BTP.Init Discharge Set.
- When OperationStatus()[BTP_INT] is set and if Settings.Configuration.IO Config[BTP_EN] is set, then the BTP_INT pin output is asserted.
- If Settings.Configuration.IO Config[BTP_POL] is set, it will assert high; otherwise, it will assert low.
- When either BTPDischargeSet() or BTPChargeSet() commands are received, OperationStatus()[BTP_INT] will clear and the pin will be deasserted. The new threshold is written to either BTPDischargeSet() or BTPChargeSet().
- At reset, the pin is set to the deasserted state.
- If [BTP_POL] is changed, one of the BTP commands must be reset or sent to “clear" the state.