Author Topic: Clock signals: short ? or match the propagation delay with other signals?  (Read 2699 times)

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Offline CreedonicsTopic starter

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Hello everyone,

so i'm making a fairly large pcb design which has many clock signals, sometimes the IC manufacturer would have documentation and would mention that the Clock signal needs to be matched to the other signals, or that it needs to be s short as possible meaning shorter than the other signals, but sometimes the manufacturer doesn't say anything at all about said clock signals.
i've been watching some videos from phil's lab and i just remarked that many of his designs have the clock signal as short as it can be, now it could be that he just found from the manufacturer that they need to be that way or it is some kind of rule that i don't know about ?
what do you guys think ? and what do you generally do about Clock signals ?

thanks everyone.
 

Online thm_w

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Re: Clock signals: short ? or match the propagation delay with other signals?
« Reply #1 on: September 01, 2023, 09:01:02 pm »
You need to be more specific, what is the part, what is the frequency of the clock signal.
If its something like low speed I2C or SPI its going to be quite forgiving.

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Online jpanhalt

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Re: Clock signals: short ? or match the propagation delay with other signals?
« Reply #2 on: September 01, 2023, 09:22:45 pm »
The Olympics don't have different clocks for men's and women's races.  A clock is just that.  If you have delays, deal with them.  Don't mess with the clock.  Of course, there is an obvious difference between synchronization and clocking.
 

Offline CreedonicsTopic starter

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Re: Clock signals: short ? or match the propagation delay with other signals?
« Reply #3 on: September 01, 2023, 10:07:14 pm »
the clocks i'm dealing with are for eMMC and QSPI & DDR3 although the DDR3 one has some good guidelines but the rest don't
 

Online thm_w

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