Congestion-Oriented Approach in Placement for Analog and Mixed-Signal Circuits

Hongxia Zhou1,  Chiu-Wing Sham1,  Hailong Yao2
1The Hong Kong Polytechnic University, 2Tsinghua University


Placement design is an essential step in VLSI design and the interaction between different modules makes it a complex process, especially for the integration of analog and mixed-signal circuits. The satisfactory placements of these circuits can be achieved by considering a series of constraints such as symmetry, and general placement constraints–alignment, abutment, preplace, boundary, range and maximum separation. Additionally, the placement result determines the routability of the subsequent routing work. Hence, routability is another important issue that should be considered during the placement phase. In this paper, we propose a new approach which expands the size of certain modules by analyzing the net congestion probability in respect of routability and satisfying the metioned constraints during the placement process for analog and mixed-signal circuits. Experimental results demonstrate the effectiveness and feasibility of our approach in solving the routability-driven placement problem.