We are doing a project based on FPGA (Spartan 3E). We are having problems on VHDL coding. We need a code such that one port gives a pulse and the other a pulse which is delayed. Please help us.
Digital implementations of Sinusoidal Pulse Width Modulation (SPWM) generators have dominated over their counterparts based on analog circuits. In this work, we present an SPWM generator based on FPGA, which is able to operate at switching frequencies up to 1 MHz (requires FPGA operation at 100-160 MHz), so it is able to withstand the high frequency requirements Switching Converters cc / ac. The proposed design occupies a small fraction of a medium-sized FPGA and therefore can be incorporated into larger designs. In addition, it has a flexible architecture that can be tuned to a variety of single-phase dc / ca converter applications. Post-arrangement simulation and experimental results confirm that compared to the SPWM generation designs proposed in the past, the SPWM generator presented in this paper exhibits a much faster switching frequency, lower power consumption and a higher Accuracy by generating the desired SPWM waveform.
FPGA is just a gate array that can be connected as the user wishes. FPGAs are used for relatively simpler operations, but a higher processing speed compared to microcontrollers. Field Programmable Gate Array (FPGA) offers the most preferred way of designing PWM Generator for power converter applications. They are basically interconnected between different logical blocks. When the design is implemented in FPGA are designed in such a way that can be easily modified if any need arises in the future. We have to change the interconnection between these logical blocks. This feature of the reprogramming capability of FPGA makes it suitable to make its design using FPGA. Also using FPGA we can implement the design within a short time and efficient hardware for rapid prototyping. Therefore FPGA is the best way to design digital PWM generators. Also the implementation of FPGA-based control schemes is less costly and therefore economically suitable for small designs.