Most FPGAs could provide configurable I/O standards in order to allow a wide range of devices to be connected and operated at different voltage levels without the need to use adapter interfaces or voltage converters, significantly simplifying the design and reducing costs. For example, the Spartan-3 FPGA from Xilinx provides various I/O bank standards like LVCMOS, LVTTL, GTL, HSTL, PCI, SSTL, LDT, LVDS, RSDS, and LVPECL that can operate at different voltage levels from 1.2 to 3.3 V.Some FPGAs incorporate a large amount of arithmetic blocks that can be low-complexity blocks such as simple multipliers or can be relatively more complex like the Digital Signal Processing (DSP) units which consist of combinations of various components like multipliers, adders, accumulators, shift registers, etc.
A DSP unit significantly accelerates the FPGA’s performance and allows achieving greater productivity and flexibility, while decreasing cost and power consumption. For instance, each Stratix II and Stratix II GX device (from Altera) has two to four columns of DSP blocks that efficiently implement multiplication, multiply-accumulate and multiply-add functions. The number of DSP blocks per column and the number of columns available depends on the device, for example, the EP2S180 device from the Stratix II family has 96 DSP Blocks, 769 9 �� 9 Multipliers, 384 18 �� 18 Multipliers and 96 36 �� 36 Multipliers. Furthermore, internal memories offer very high relative speed compared with external memories. Current FPGAs contain large amounts of internal memory blocks, for instance, up to 34 Mb of internal RAM in the Virtex-6 devices from Xilinx.
Other memory types can be found such as Random Access Memory (RAM), Read Only Memory (ROM) or shift registers. In addition the designer can implement other memory structures like First In First Out (FIFO).The cost reduction of the FPGAs, their increasing capabilities and the possibility of improving the performance of sensor systems with specific hardware technologies have led their use in new application fields related with sensors to clearly increase. This paper presents a state of the art overview of the research on sensor systems based on FPGAs in Spain. A great number of applications are integrated in systems that require high data throughputs. Application fields such as image processing and wireless sensors can take advantage of the increasing density of the chips.
Nowadays, it is possible to find not only applications in research laboratories, but Cilengitide also in real sensory systems. It is possible to find new fields with growing demand such as thermal management, automotive, robotics, industrial control, medical, reduction of power consumption, etc. All these sensor-based applications employ FPGAs with different purposes, as it will be described throughout the paper.