Syntill8 licenses Mentor Graphics' M8051 family of microcontroller cores. All the cores in the product range are compatible with the Intel 8051 architecture. They are implemented as soft cores, ready for integration into customers' SoC products.


We offer two types of 8051 design: the M8051 and M8052 are designed to provide precise compatibility with discrete Intel devices, whereas the M8051W and M8051EW offer enhanced speed and reduced power consumption, together with usability extensions.

The current portfolio is differentiated according to our perception of customer demand. At one end of the range the M8051 sets pin-for-pin and clock-for-clock compatibility with the original Intel devices as its highest design requirement. At the other end of the scale Syntill8 has designed the M8051W and M8051EW to provide a fast, low-power solution that remains memory-cycle compatible with Intel's 87C51. An overriding design goal has been to produce the best performing true 8-bit designs, which use only 8-bit components and memory resources.

Clocks per Machine Cycle 12 12 2 2
External Address Space 0-64k 0-64k 0-1M 0-1M
Internal Data Memory 0-256 0-256 0-256 0-256
Multiplexed Externl Memory Bus
Wait State Support    
Synchronous Memory Support    
Interrupt Sources 5 6 5-25 5-25
Non-maskable Interrupt    
Interrupt Levels 2 2 3/5 3/5
Data Pointers 1 1 1/2/4/8 1/2/4/8
I/O Ports 32 32 0/32 0/32
Timer Counters 2 3 0/2/3 0/2/3
Serial Port 1 1 0/1 0/1
Memory Banking
External SFR Interface
On-chip Debug