| 摘要 |
A multilevel clock tree uses a temporary clock buffer or reference signal in a clock tree deskew circuit to dynamically minimize skew in a variable delay clock signal that synchronizes operation of synchronized circuit components of an integrated circuit. There are multiple temporary clock buffer signals at each level of the multilevel clock tree. Skew between the temporary clock buffer signals are minimized by providing identical path lengths and path geometries at each level of the temporary clock buffer. The clock tree deskew circuit reduces the clock tree skew, on a level by level basis, in repeated intervals over a period of time. When each level of the tree deskew circuit is deskewed, that level of the clock tree deskew circuit is then turned off to prevent unnecessary further adjustments to the clock signals, but can be turned back on when conditions change that alter the clock tree skew. The clock tree deskew circuit adjusts the variable delay clock buffer signal of each pair toward the temporary clock buffer signal of the pair to reduce the skew between the two clock buffer signals. After a predetermined number of adjustment cycles, the overall clock skew of the variable delay clock buffer signal is minimized by repeated adjustments. The variable delay clock buffer signals of each level may be optionally set as conditions warrant.
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