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#sky130
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# sky130
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Andrew Zonenberg

06/08/2021, 10:01 AM
Has anyone played with digital delay lines on SKY130? What would a reasonably achievable delay per tap be?
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Tim Edwards

06/08/2021, 4:06 PM
Take a look at the so-called digital PLL in the caravel design (actually a frequency-locked loop). It has a trimmable ring oscillator which, if you unwrap the loop, is in the configuration you describe for a digital delay line.
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Andrew Zonenberg

06/08/2021, 4:24 PM
What's the tap resolution?
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Tim Edwards

06/09/2021, 7:45 PM
My behavioral verilog for the ring oscillator in the caravel repository has these numbers: 23.85ps per trim bit.
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Andrew Zonenberg

06/09/2021, 8:18 PM
~24 ps, OK. Good to know