HOME       UP       PREV       NEXT (Clock Domain Crossing Bridge)  

Clock Tree

The clock tree delivers a clock to all flops in a domain with sufficiently low skew to avoid shoot-thru. This is achieved by balancing wire lengths between the drivers.

The clock frequency is a multiple of the external reference which is commonly sourced from the piezo-effect of sound waves in a thin slice of quartz crystal.

This slide was not lectured in 2009. However, later on we talk about having a programmable clock frequency, so it's worth noting that the multiplication factor of 10 illustrated in the slide can be variable and programmed in some systems (e.g. laptops).

(C) 2008-10, DJ Greaves, University of Cambridge, Computer Laboratory.