One resion might be Its difficult to test JKff than dff.
Timing analysys for jkff will be issue too!
All tools make basic assumption that the logic they are working with
contains only dff.
1. Synthesis tool, at least DC, will take JK-FF during the synthesis if needed.
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2. TSMC 0.18um standard cell library (Artisan) also has JK-FF.
TSMC 0.13um and after (Artisan) standard cell library do not contain JK-FF.
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