A Design Style for VLSI CMOS

CMOS is an attractive technology for the realization of VLSI systems. However conventional static CMOS design techniques lead to circuits which are slower and much less densely packed than equivalent NMOS circuits. After a brief review of precharge-discharge techniques, a novel method for designing clocked dynamic CMOS is described. This uses a four-phsse clocking scheme that is free from race and charge-sharing problems and results in faster, more compact layouts. A test chip and a full custom 25 000 transistor serial signal processing chip have been designed using this technique. Results obtained by probing the test ship are presented.