Programmable System on Chip Applied to Low Frequency Rfid Interrogation

Systems on chip, by definition, unite a number of functions and occasionally, sensors or actuators, into a unified, compact, lower-power solution to a signal processing problem. Recent efforts have seen the research, development, and commercialization of systems on chip that are sufficiently programmable and flexible to address a wider variety of applications and signal processing problems than their fixed configuration counterparts. In this paper, we present the application of a recently commercialized SoC effort to the problem of interrogating a low frequency radio frequency transponder, using an amplitude shift keyed encoding scheme. Within this representative application, the following reductions are realized compared to a discrete implementation: power 64%, cost 71%, component count 96%, and size 95%. In addition, the better matched components in the SoC provide a 25% improvement in read range over the discrete implementation of the radio frequency identification interrogator. INTRODUCTION Modular and user-defined design of electronic circuits is progressing rapidly in the integrated circuit industry. Reconfigurability and programmability of systems is most often associated with digital logic, such as in the popular Field Programmable Gate Array (FPGA). Modular, programmable, and mixed signal Systems on Chip (SoC), however, are gaining popularity in addressing a wide variety of user-defined applications, alongside their purely digital counterparts. The ability to dynamically configure analog circuit blocks, digital circuit blocks, and the interconnections between them on a single integrated die is key to facilitating rapid product development while maintaining the high level of precision and performance afforded by integrated circuits as compared to assemblies of discrete circuits. In addition to decreasing development time, programmable mixed signal SoC offer the potential to significantly reduce power, component count, size, and cost of a wider variety of systems than purely digital SoC can address. Field programmable digital logic has been available commercially for almost two decades and has reached systemlevel configurability at the microprocessor level[1]. Field programmable analog arrays began to gain popularity in the late 80’s and early 90’s in the research community[2][3] as well as some representation in industry patents[4][5] and products[6][7]. Shortly thereafter, the advent of mixed signal programmability began with the ability to interface digital and analog signals (Actel patent[5] and AMD patents[9][10]) and progressed to the exchange of analog and digital signals on the chip itself [11] [12]. An important step forward in the programmable, mixedsignal SoC are the PSoCTM Microcontrollers from Cypress MicroSystems (CY8C2xxxx part family). These parts are the first to offer comfigurable analog and digital blocks in a Flash RAM μC SC CT CT CT CT