The CPU clock offers the unique feature of smooth, glitch-free transitions from one frequency to the next, making this the ideal device to use when slowing the CPU speed. The AV9154A makes a gradual transition between frequencies so that it obeys the Intel cycle-to-cycle timing specifications for 486 and Pentium systems. The AV9154A-42 and AV9154A-43 devices offer features specifically for green PCs. The AV9154A-42 and -43 have a single pin that, when pulled low, will smoothly slow the 2XCPU clock to 8 MHz. This is ideal for dynamic DX microprocessors. The AV9154A-43 not only has the slow clock feature, but also offers a glitch-free stop clock for static SX microprocessors. The STOPCLK# pin, when pulled low, enables the 2XCPU clock to go low only after completing its last full cycle. The clock continues to run internally, and will be output again on the first full cycle immediately following stop clock disable.