A contactless system is described in which energy is scavenged from an electromagnetic field provided by a proximate reader device. An embedded processor and a volatile memory circuit within a near field communication (NFC) controller are operated using the scavenged energy. Parameter data from the proximate reader device may be acquired while conducting a near field communication transaction. A non-volatile memory (NVRAM) server is coupled to the NFC controller and also operates using the scavenged energy. Parameter data may be stored within the NVRAM server by sending a command and the parameter data from the NFC controller to the NVRAM server. At the completion of the transaction, the electromagnet field may be removed and all parameter data stored within the NFC controller will be lost. However, the next time the electromagnetic field is applied, the NFC controller may retrieve the parameters from the NVRAM server by sending a command.