Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [clock]

A digital signal that goes high and low at a specific frequency.

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Why are clocks used in computers?

As I know, a clock controls all of the logic operations, but it also limits the speed of a computer because the gates have to wait for the clock to change from low to high or high to low depending on the component. If no clock was incorporated, the…
skyler
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How do electronic devices keep track of time without power?

There's laptops, PCs, microcontrollers and a lot of other things that can be plugged out and plugged in without a battery. But how does the system clock still keep track of time without anything to power it?
Loogai
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Frequency of a MCU is higher than frequency of a quartz

How is it possible that in a LPC3141 MCU the MCU has frequency 270MHz while the 12MHz quartz crystal is used in oscilator (inside the clock generation unit)? Makes no sense to me... Could anyone please explain.
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Clock signal purpose

I'm a mechE and have been trying to get into the digital world for a bit and need to know why a system would need a clock signal at all. For example, if I have some bit of code getting executed on a device, why can't the logic gates performing code…
shakeNbake
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How can pipelining hurt the clock frequency?

As I understand it, pipelining is used to speed up the clock frequency by processing more instructions at once, and longer pipelines should improve the clock frequency. However, my instructor mentioned that in some cases pipelining could actually…
Ceasar
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Clock generation of 9 phases of clock

I am trying to come up with a circuit that generates a series of clocks, I will need these different clocks on different pins. The circuit must be configurable in terms of frequency and phase shift (see below) All clocks are synchronized. The first…
Ktc
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At which point is it useful to switch from many clocks to a clock tree?

In the IoT induced craze I'm doing some messy kind of interface bridge board. As in: USB, Bluetooth and various other serial things on a 60×60mm space. At this moment I would have: 25MHz for the MCU Some frequency for the external UARTs (maybe the…
Lorenzo Marcantonio
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Clock circuit layout techniques

I am prototyping (point to point wiring only) a digital circuit with multiple shift register IC's to be clocked simultaneously at 500Khz. The distance between the clock source and the IC clock pins is going to be about 5 inches max. How should I lay…
Fred Paine
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Why create clk and clk NOT with 2 inverters instead of 1?

I see many circuits use this topology Why dont we use just only one inverter like this: Thanks very much!
Earthgod
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150 MHz LVPECL Clock

I am using a SAS expander IC. In the datasheet, it is given to use a 150 MHz LVPECL clock with specifications as attached in the snapshot. Can somebody please explain how to use common mode & differential specifications while choosing a LVPECL…
Oshi
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Clock generator/synthesizer, Frequency generator/synthesizer. What is the difference?

EDIT: Question simplified: What is the difference between frequency generator and frequency synthesizer. What is the difference between clock generator and clock synthesizer.
Gima
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8284 Clock Generator

I am studying the 8284 clock generator and see how it works with the 8086. But before I connect the two chips together, I want to verify the 8284 first. So I placed the 8284 on the breadboard as follows: Here are my questions, any help is…
franfran
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Analogue clock position sensing

I want to control an analogue clock movement with a microcontroller. A Lavet motor is used to advance the hands. The issue is detecting where the hands are. I noticed that some radio controlled clocks move the hands to midnight before moving them to…
user
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Common clock signal to several components over long PCB lines

How to drive a clock signal to 20 digital microphone. The clock is generated from FPGA and about 3MHz frequency. First mic's line 2cm and last one's 15cm away from FPGA clock out pin. Also all mics should be sync. FPGA drive strength could…
Berker Işık
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Can I use a common Clock pin on my micro-controller project instead of separate clock pins?

In my Propeller project, I have the following devices, with the related pins: DS1302 RTC SClk - IO - CE Micro SD Card SClk - CD - CS - DI - DO SPI SRAM x 2 SClk - SO - SI - CE PS2 Mouse Clock - Data PS2 Keyboard Clock -…
Zeddy
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