PCB的指定距离布线

THE POINTED-LENGTH ROUTING ALGORITHMS ON PCB

控制时钟偏差是提高巨型机主频的关键技术之一，在PCB上利用指定距离布线算法调整时钟到各寄存器的连线延时是实现这一技术的有效途径．本文提出“两段布线”和“挤压延长”两种新的指定距离布线算法．实际应用表明，它比传统算法布线速度快，布线成功率高．

Reducing clock skews is one of the key techniques to increase clock fre-quency. The pointed-length routing algorithms can adjust the wire delays from clockto each register. The conventional methods have the following steps: 1) routlng theclock wires initially, 2) the wire delays analysising, 3) ripping up the wires, 4)pointed-length routing of the wires according to the analysis. In this paper, twonew pointed-length routing algorithms are presented. The first algorithm is basedon the following fact. If (x0,y0) is the start point, (x1,y1 ) is the final point and Lis the pointed length, L must be greatet than So, a point(x, y) can be found, which satisfies(x, y), (x0,y0) and (x, y), (x1,yl ) are routed respectively. The basic idea of thesecond algorithm is described as follows. The wire is routed firstly. If the routedlength l is less than L-2, the wire is increased by 2. The process is repeated until. The experiments show that the algorithms run fast and the results aregood.