DTB Multiplexer is a component within an NXP chip called the BAP3. This component provides a testing functionality for the chip. This component is purely combinational, and requires no clock, however this makes the component wiring-costly. This high wiring requirement leads to the area constraint imposed by the wiring demand rather than cell area, and this also leads to the DTB multiplexer reducing the placement area available for other modules. In this thesis, the wiring area is going to be estimated as the amount of congestion, which would cause detour in the design which results in extra wiring. In this thesis, DTB multiplexer is placed by external method instead of using the place and route tools usually used by the design team. Instead, the placement is done on MATLAB which is later ported to the place and route tools using script. The placement algorithm implemented in MATLAB is primarily based on two algorithm, Dplace for initial preplacement, which in turn utilizes diffusion preplacement algorithm, and modified C-ECOP for the congestion reduction. More detailed congestion estimation done by using an additional routing estimation algorithm which is based on One-Steiner routing algorithm. The result indicates that the modified C-ECOP can be used to reduce congestion, thus wiring area when paired with a good initial placement algorithm, but the initial placement algorithm and detailed congestion estimation algorithm with one-steiner could be further improved, and further work is needed to integrate the result with commercial