The 8051 CPU architecture and instruction set was first developed by Intel and released in 1980. For the next 34 years it has been adapted and optimized for higher performance. Being a mature and proven architecture, it has been adopted by numerous silicon providers and is one of the most popular 8bit CPUs to this day. The 8051 is a Harvard Architecture device, with CISC instruction set. Many IP core providers also supply 8051 binary compatible cores as VHDL or Verilog RTL such that it can be implemented in an FPGA or custom ASIC.
We have a long history of working with 8051 cores and have integrated them into many of our custom designs. Our 8051 can be implemented within our via configurable digital logic with a single via mask. Customers chose 8051 because it is cost effective both from a NRE and unit price perspective, is a very low power CPU and easy to program.