About the founder

VLSI Concepts was founded in 1995 by Dr. Edward L. Hepler

Dr. Hepler began his career as a Member of Technical Staff in the Processor Design laboratory of Bell Laboratories where he helped design high reliability processors used in electronic switching systems. From there he moved to the Space Systems Division of General Electric and then to Commodore Business Machines where he developed chips for next generation Amiga machines. ...


The V805x is a synthesizable VHDL (soft) core design which is object code compatible with Intel's popular 8-bit 8051 microprocessor. The V805x is intended to be used in system-on-a-chip applications constructed using gate-arrays or standard cells. It should be especially interesting to designers who currently use 8051s in embedded control applications and want to integrate its functionality with other designs/peripherals/etc. onto a single chip (ASIC).

The V805x is a fully synchronous design and contains no microcode; all control is implemented via state machines. It is written in synthesizable VHDL using IEEE standard libraries. It uses a single clock.

The V805x is significantly faster than the original 8051. It can use a faster clock speed than the original and uses fewer clock cycles than the original. The V805x implements the 8051 CPU; you can configure the peripherals you need for your applications (add more ports, timers, peripherals, etc. to make a custom version for your design needs).

The design kit includes the synthesizable VHDL model, a sample synthesis script, a sample constraint file, a VHDL test bench, and test stimulus files.

VLSI Concepts can provide customization of the design, if requested.

Design and integration assistance is also available from VLSI Concepts.


  1. Object code compatible with 8051
  2. Fully synchronous design
  3. No microcode; All control via state machines
  4. On-Chip Debug assist hardware included in design
  5. "ICE"-like functions via JTAG access port
  6. Customize the design to your needs
  7. Written in synthesizable VHDL - no microcode

Contact us for more information!