Yu Liu Thanyapat Sakunkonchak Satoshi Komatsu Masahiro Fujita System level design language extensions for timed/untimed digital-analog combined system design. 130-133 2005 conf/glvlsi/2005 ACM Great Lakes Symposium on VLSI http://doi.acm.org/10.1145/1057661.1057693 db/conf/glvlsi/glvlsi2005.html#LiuSKF05