TY - JOUR
T1 - Analysis and optimization of structured power-ground networks
AU - Su, Haihua
AU - Gala, Kaushik H.
AU - Sapatnekar, Sachin S.
PY - 2003/11
Y1 - 2003/11
N2 - This paper presents an efficient method for optimizing power/ground (P/G) networks by widening wires and adding decoupling capacitors (decaps). It proposes a structured skeleton that is intermediate to the conventional method that uses full meshes, which are hard to analyze efficiently, and tree-structured networks, which provide poor performance. As an example, we consider a P/G network structure modeled as an overlying mesh with underlying trees originating from the mesh, which eases the task of analysis with acceptable performance sacrifices. A fast and efficient event-driven P/G network simulator is proposed, which hierarchically simulates the P/G network with an adaptation of PRIMA to handle nonzero initial conditions. An adjoint network that incorporates the variable topology of the original P/G network, as elements switch in and out of the network, is constructed to calculate the transient adjoint sensitivity over multiple intervals. The gradients of the most critical node with respect to each wire width and decap are used by a sensitivity-based heuristic optimizer that minimizes a weighted sum of the wire and the decap area. Experimental results show that this procedure can be used to efficiently optimize large networks.
AB - This paper presents an efficient method for optimizing power/ground (P/G) networks by widening wires and adding decoupling capacitors (decaps). It proposes a structured skeleton that is intermediate to the conventional method that uses full meshes, which are hard to analyze efficiently, and tree-structured networks, which provide poor performance. As an example, we consider a P/G network structure modeled as an overlying mesh with underlying trees originating from the mesh, which eases the task of analysis with acceptable performance sacrifices. A fast and efficient event-driven P/G network simulator is proposed, which hierarchically simulates the P/G network with an adaptation of PRIMA to handle nonzero initial conditions. An adjoint network that incorporates the variable topology of the original P/G network, as elements switch in and out of the network, is constructed to calculate the transient adjoint sensitivity over multiple intervals. The gradients of the most critical node with respect to each wire width and decap are used by a sensitivity-based heuristic optimizer that minimizes a weighted sum of the wire and the decap area. Experimental results show that this procedure can be used to efficiently optimize large networks.
KW - CMOS integrated circuits
KW - Circuit optimization
KW - Circuit topology
KW - Power distribution
KW - Reduced order systems
KW - Sensitivity
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U2 - 10.1109/TCAD.2003.818372
DO - 10.1109/TCAD.2003.818372
M3 - Article
AN - SCOPUS:0242720636
SN - 0278-0070
VL - 22
SP - 1533
EP - 1544
JO - IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
JF - IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
IS - 11
ER -