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I'm not quite certain what's the use case for most soft CPU's on FPGA-s. My experience is from the other side (Xilinx) and it's more than half a decade old, how

I'm not quite certain what's the use case for most soft CPU's on FPGA-s. My experience is from the other side (Xilinx) and it's more than half a decade old, however looking at stuff it doesn't seem to me that things have changed that much. What 2 useful CPU designs I used were the PicoBlaze, a bespoke microcontroller with a weird architecture designed to take advantage of FPGA implementation details, and was ridiculously tiny, like a RAM block + a few slices worth. The other one was the ARM Cortex A9 core physical core on the Zynq FPGA. MicroBlaze, Xilinx's own big soft-CPU core was a combination of slow and large, with a buggy compiler to boot.

rkangel 5y ago
> MicroBlaze, Xilinx's own big soft-CPU core was a combination of slow and large, with a buggy compiler to boot. Agree, but Xilinx now basically put 2+ ARM cores in everything which solves the problem extremely well.
brandmeyer 5y ago
> I'm not quite certain what's the use case for most soft CPU's on FPGA-s. They are used for state machines and control algorithms that are complex enough that you don't want to implement them in HDL. High-speed interface (eg, DDR4, high-speed ADC) initialization and training is a common example.