IBIS spec 5.1里有介绍 / ^1 Y h3 }) w+ B, [) }Section 7 describes the package model format of IBIS 7 Y4 l$ c# h0 n
Version 2.1 and a subsequent extension. Package models can be formatted within .ibs files or can , K! @1 I* {+ g+ e# I2 zbe formatted (along with the Section file header keywords) as .pkg files.