This paper describes the design and implementation of an integrated circuit for a new optimum decoding algorithm for Manchester code. It is shown that the proposed algorithm is using the symmetrical properties of the Manchester code and provides 3 dB energy gain in comparison with the hard decision decoding. The decoder has been designed using a 2.4 μm CMOS technology and the implementation and performance results have been tested for a 10 Mbit/sec information rate which is similar to the Ethernet specification.