FPGAs are usually a better situational substitute for an ASIC than a CPU. Relative strengths of FPGAs: * Complete control over pin assignments. * Complete con

FPGAs are usually a better situational substitute for an ASIC than a CPU. Relative strengths of FPGAs: * Complete control over pin assignments. * Complete control over PLLs and clocks. * Complete control over transitioning clock domains, and other timing characteristics, skew, etc. * Convenient SoC features: DSP multipliers, SRAM, on chip flash memory, ADCs, etc. and the ability to run a soft core CPU on chip as a convenience and/or to give it direct access to various clock domains. * All hardware features including all listed above are in-system programmable. FPGAs are excellent glue, and the smaller sizes of MAX-10 (or equivalent) are cheap and have a small footprint. If you're doing hardware design that uses CPUs, adding an FPGA can vastly improve the flexibility of your design. They are great for interfacing to other dedicated chips. They also make good DSP chips, but if they strictly only did that they wouldn't be nearly as useful.