Apparatus for harvesting and using power in a near field communications mode, comprising: a host device ; a plurality of operating components contained in the host device, the plurality of operating components comprising a processor and a memory , each configured for operation with the host device; and a first near field communication (NFC) device in the host device configured to be selectively serially coupled to the plurality of operating components; the first NFC device being configured to harvest energy from a second NFC device and to convert the harvested energy to electrical power; the first NFC device being further configured to selectively power on only one operating component of the plurality of operating components at a time using the converted electrical power; the first NFC device being further configured to receive data from the second NFC device ; the first NFC device being further configured to power on a first operating component based on the data received from the second NFC device ; the first NFC device being configured to receive first data from the first operating component when the first operating component is powered on; the first NFC device being configured to power off the first operating component when the reception of the first data has been completed; the first NFC device being configured to, based on the first data, power on a second operating component after the first operating component is powered off and to transfer the first data to the second operating component; the second operating component being configured to operate on the first data and return third data to the first NFC device ; the first NFC device being configured to power off the second operating component after the third data has been returned to the first NFC device ; and the first NFC device being configured to transfer the third data to the second NFC device . a host device ; a plurality of operating components contained in the host device, the plurality of operating components comprising a processor and a memory , each configured for operation with the host device; and a first near field communication (NFC) device in the host device configured to be selectively serially coupled to the plurality of operating components; the first NFC device being configured to harvest energy from a second NFC device and to convert the harvested energy to electrical power; the first NFC device being further configured to selectively power on only one operating component of the plurality of operating components at a time using the converted electrical power; the first NFC device being further configured to receive data from the second NFC device ; the first NFC device being further configured to power on a first operating component based on the data received from the second NFC device ; the first NFC device being configured to receive first data from the first operating component when the first operating component is powered on; the first NFC device being configured to power off the first operating component when the reception of the first data has been completed; the first NFC device being configured to, based on the first data, power on a second operating component after the first operating component is powered off and to transfer the first data to the second operating component; the second operating component being configured to operate on the first data and return third data to the first NFC device ; the first NFC device being configured to power off the second operating component after the third data has been returned to the first NFC device ; and the first NFC device being configured to transfer the third data to the second NFC device . <EOS>