The term soft-processorⁱ is used to refer to microprocessors which are not provided to the customer as a physical chip but are instead provided to the customer in some kind of synthesizable description, typically an HDL such as VHDL or Verilog. Typically this is done so that the customer can customize the processor based on their specific needs. For instance, the MicroBlazeⁱ soft-processorⁱ from Xilinxⁱ allows the customer to optionally include components such as a FPUⁱ or an MMUⁱ.

The ability to customize to the customer's specific needs provides a significant advantage to soft-processors over traditional processors. By only including the needed functionality, system designs can be reduced in size, and thus, can be most cost effective. However, soft-processors do typically have the disadvantage of being significantly lower performance than their traditional counter-parts.