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发表于 2004-4-22 22:56:18
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about gated clock
I do not agree. In our ASIC design, the gated clocks are used extensively - almost each FF has to be gated. It is the most efficient way to save power. Furthermore, do not let tool (like Synopsys Power Compiler) insert clock gating cell automatically. It will cause lots of problems, i.e. formal verification.
Another way to solve your problem is to re-arrange the clock buffer tree, for example, if the skew is big due to too many flop load, you can use two clock buffer to drive them.
One design rule is use registered clock enable signal for clock gating cell. It shall prevent glitch problem on clock enable. I do not understand why you said STA could not report clock gating cell setup/hold violation. |
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