The device provides the control to generate the VBUS current pulse protocol to communicate with adjustable high voltage adapter in order to signal adapter to increase or decrease output voltage. To enable the interface, the EN_PUMPX bit must be set. Then the host can select the increase/decrease voltage pulse by setting one of the PUMPX_UP or PUMPX_DN bit (but not both) to start the VBUS current pulse sequence. During the current pulse sequence, the PUMPX_UP and PUMPX_DN bits are set to indicate pulse sequence is in progress and the device pulses the input current limit between current limit set forth by IINLIM or IDPM_LIM register and the 100mA current limit (I_{INDPM100_ACC}). When the pulse sequence is completed, the input current limit is returned to value set by IINLIM or IDPM_LIM register and the PUMPX_UP or PUMPX_DN bit is cleared. In addition, the EN_PUMPX can be cleared during the current pulse sequence to terminate the sequence and force charger to return to input current limit as set forth by the IINLIM or IDPM_LIM register immediately. When EN_PUMPX bit is low, write to PUMPX_UP and PUMPX_DN bit would be ignored and have no effect on VBUS current limit.