Motor Speed Control with FPGA and Optical Sensor

Welcome to CR4 harjasmeet_s.

That said, you might need to provide a bit more information to get a reasonable response. What hardware are you using? is this planned to be in a PLC? Do you have the PWM? do you plan to build from scratch? Are you simply looking for someone to write the code?

well, apparently I'm no help at all.

Why an FPGA? Nothing happens in any 'ordinary' kind of motor* that needs that kind of speed. What rpm are you working with? A simple micro with built-in RAM & EPROM could do most motor control apps standing on its head - and it would be a lot more flexible. Are you familiar with PICs?

Can you program in BASIC or C (or, perchance, assembly language)? Is this a hobby or one-off on-the-cheap/in-house use/educational project?**

What provides your setpoint for the speed? What kind of optical sensor are you using? Please give some more information.

* This is perhaps excluding 100,000+ rpm ultra-high-speed motors.

** If you've answered 'no' to both of these, you're probably in the wrong job.

I feel that you don't know exactly what a FPGA is. It is a large scale integration of logic circuits that can be programmed once or more times, according to a schematic diagram or a language (VHDL) that puts in words the above mentioned schematic. It is used for situations in which you have a lot of logic inputs and outputs. The FPGA itself doesn't have the possibility to run a program as a microprocessor or a microcontroller do. There is possible to have a microcontroller embedded, which would rise the price of an FPGA.

Unless you have to control an Airbus A330-200, you better use a microcontroller, as JohnDG advised you.