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

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20 views

Programmable clock generator IC and reference circuit

I need a clock source for some data converters (DAC, ADC), and I would like the clock frequency to be as configurable as possible. I assume this would involve some kind of clock multiplier/divider, ...
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1answer
35 views

Rise/Fall time of GP Pins

Are rise/fall times typically affected by the clock speed. That is if I have a AVR at 16 MHz will it have a different rise/fall time than the same AVR at 32kHz?
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1answer
55 views

Carry-lookahead adder in VLSI, Static VS Dynamic?

I study one course about VLSI. in adder lecture my profesor talk about Adders. in Carry-lookahead adder first talk about static version, as follows: at next we start about dynamic version of CLA ...
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1answer
36 views

Generating a clock from timer using PWM

I am using CC2640 from TI in one of my designs. As per the datasheet, I can output a clock of maximum 32KHz to any external circuit/IC. As per my design, I Need to provide 1MHz clock to a sensor. ...
3
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1answer
63 views

ATSAM3X8E: Custom Arduino Due Design

I'm currentlry doing a redesign of the Arduino Due board to include some additional features I need. Browsing through the Datasheet of the ATMSAM3X8E atmel chip, I noticed that the 12Mhz Oszillator ...
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2answers
356 views

When would be occasions to use a lower clock given that high speed would always be preferable?

I am using STM32F0 MCU and STM32 CubeMX configurator. I encountered the clock configuration below When would be occasions to use a lower clock speed? Wouldn't faster always be preferable?
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1answer
81 views

Should I use an FPGA output for an MCU Clock?

We are laying out a board that was designed ages ago, the main purpose of the update is for part obsolescence. The board has several PIC uC's on it as well as an FPGA. Each of the PIC's needs a ...
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4answers
293 views

How do computers deal with RAM latency?

The clocks of CPU's have gotten faster than RAM. So computers have to wait a particular number of clock cycles between sending an address and receiving data. But how does a computer know how many ...
-3
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2answers
75 views

Nixie Tube Clock Kit [closed]

This is my first electronics project. I bought a nixie clock kit from http://nixieclock...eu/. I connected everything and the led lights come on instantly but the nixie tubes and leds in between the ...
2
votes
1answer
19 views

Updating of a memory cell / synchronization with a clock

I'm wondering how computers actually work on a gate-level. I can see how a storage mechanism could be built from logic gates (e.g. SR NOR latch). What I'm wondering: how do values in memory cells get ...
0
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2answers
37 views

Source synchronous vs Common clock methodology in Physical design

I understand common clock and source synchronous clock. From this link http://referencedesigner.com/books/si/common-vs-source-sync.php. What i do not understand 1) How is maximum frequency attained ...
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3answers
56 views

Creating a +5V/-4V Clock with a PIC Micro

I'm working on a project to drive a CCD array which needs a particular signal with a high of +5V and a low of -4V, changing fairly rapidly. I'm using a PIC18F4620, which as far as I'm aware, looking ...
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0answers
66 views

Is there a way to fine tune the frequency of a crystal oscillator?

I have a cheap alarm clock at home. I notified that it got about 10 min of delay every two weeks (I have to re-setup time again and again). I tear it down and found out it is driven by a crystal and ...
0
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1answer
35 views

Getting Raspberry Pi or Arduino to control three clock hands separately

I want to make an analog subway countdown clock. The idea is to have an ordinary clock with three hands. These hands will point to the number of minutes before the next, second next, and third next ...
0
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1answer
32 views

AM437x/AM335x Audio clock generation

For some ADCs and DACs I'm using I need a 24.576MHz clock (96kHz * 256). Obviously I can use a low jitter audio clock generator. However, I have a AM335x processor available that claims to have a low ...
7
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5answers
2k views

How do I drive 14.3Mhz clock input from 10MHz?

I intend to use an IC which requires 14.3MHz clock input, but want to drive it from a stable 10MHz source - derived from GPS. How do I turn the 10MHz clock into the 14.3MHz that the IC requires?
3
votes
2answers
151 views

Choosing crystal, strangely narrow requirements in MCU datasheet?

I am making a prototype using the Atmel ATSAM4S2B microcontroller, but I am having trouble choosing a crystal. I need a 12MHz crystal to use the integrated USB module. The problem is, in the ...
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1answer
50 views

How does a clock cycle delay skip a computer instruction?

This is from the Wikipedia entry on Pirate decryption The signals moving between the smartcard and the receiver can be easily intercepted and analyzed. They can be vulnerable to a "glitch" by ...
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1answer
68 views

How to Sycnhronize STM32F4 Clock with PC Clock

I'm using 3 STM32F401RE to synchronize their clocks. My desired accuracy is of 1ms and even lesser like 0.1ms. This device is connected to PC via USB port. Question 1 : So I would like to know if I ...
0
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1answer
68 views

Precision timing using arduino and external clock

I'm working on a very time limited project (8 weeks). Basically I need to perform measurements and save to memory. 2 identical boxes, 4 hours and no wireless or wired connection. Each box is ...
0
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1answer
35 views

Automatic and manual clock managing. Errors with ring counter but not with 4-bit counter

I'm building an 8 bit computer and I've just developed the clock. I used a NE555 (datasheet) with some other integrated (74 series) to manage it. The operator could stop signal from 555 (with a ...
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1answer
71 views

Arduino based clock with 4 pieces 4" 7 Segment LED Displays

I was going through multiple tutorials on how to create an Arduino clock with 7 segment displays. I planned to build one and purchased 4 large (4 inches) 7 segment 1 digit displays. The displays run ...
3
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1answer
72 views

Dividing a clock in Verilog - is it OK?

Dividing a clock down in Verilog is a basic exercise, and there are loads of answers online about how to do it. What I want to know is whether it is OK to use a clock that has been divided down using ...
0
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1answer
56 views

555 timer digital clock

How would you go about connecting a 555 timer to a circuit with a 16x2 LCD display, which is already connected, to create a digital clock that counts the time? Do you have a sample of how this code ...
0
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1answer
99 views

DDRx Memory: Memory Clock vs I/O Bus Clock?

When referring to DDR/DDR2/DDR3/DDR4 memories, I am not able to understand the difference between memory clock and I/O clock. As per: https://en.wikipedia.org/wiki/Double_data_rate DDR-200 - Memory ...
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1answer
27 views

Confusion with PIC32MX1XX/2xx datasheet information (clock source for USB)

Maybe there are some experienced "wolves", who could help out to clear out confusion about internal/external clock sources. Particularly, I got lost while reading PIC32 family reference manual, ...
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1answer
74 views

maximum clock frequency for a sequential circuit

This is the all question. I thought that because Tcq>Th we will only count Tcq. If we need to know the minimum clock period, we should calculate the duration from the beginning to the output of ...
0
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1answer
57 views

Full-wave rectification for clock signal from wall power

I have built this power supply and clock signal extractor exactly as shown: http://electronics.howstuffworks.com/gadgets/clocks-watches/digital-clock4.htm I have double-checked this and the rest of ...
2
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1answer
54 views

Making a positive edge clock pulse with a button?

Is it possible to have an input, say a button, that does one positive edge clock pulse? So I want to press this button once and it does a 0->1->0. I can't think of anyway to do it because it changes ...
0
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1answer
112 views

STM32F4 clock behaves very strangely

I can not find a solution for why STM32F427ZIT6 clock changes during operation. I am using external 8 Mhz crystal. Should I rather look for a error in software or hardware? I have a little code, ...
0
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2answers
135 views

STM32F4 clock 60Mhz

I want to set my STM32F446 controller his clockfrequency to 60MHz. I thought I could do it, but without results. I am using an STM32F446 -nucleo board. I used STM32CubeMX to generate my code. After ...
0
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1answer
50 views

Digital Clock - set time x hours ahead?

I have a digital clock made from an electronic kit - it has 3 buttons (1 to set the time, 1 to set alarm, 1 to cancel the alarm). I want to be able to set it so every time it is connected to power ...
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1answer
131 views

Need Help In Creating and Debugging a 8Mhz CLK Circuit

I want to create a CLK generator circuit that will work at 8Mhz. I'm following this design (from http://www.electronics-tutorials.ws/oscillator/crystal.html): My crystal is 8Mhz HC49/US, with 20pF ...
3
votes
1answer
72 views

Why is my VHDL clock signal so far off from what I thought it would be?

I'm new to FPGA and VHDL. The following code was supposed to be 5MHz but I'm getting 4.167MHz on my scope. The FPGA board I ...
2
votes
1answer
44 views

In which physical unit is 'clock drift' measured?

I would like to model a clock signal with an drift parameter in my digital simulation. The current implementation handles: frequency / period phase -360.0 .. 360.0 degree duty cycle 0.0 .. 1.0 ...
-1
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1answer
104 views

Clock and data vs rx and tx communication

I'm working on a project in which I have to make two pic10f200 microcontrollers communicate via serial communication lines. I know that with Arduino you interconnect the two board's rx and tx lines, ...
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0answers
53 views

Cycles lost on clock domain crossing

I have a MAC (VHDL) connected to the PHY through RGMII (so the clock for this communication is 125 MHz). The MAC outputs every byte at a rate of 200 MHz, so there is some clock domain crossing here. ...
0
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1answer
70 views

frequency divider by 42 with 50% duty cycle

I want to design a clock divider by 42 from flip flops. Is there a way to do that while still gets 50% duty cycle?
0
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2answers
135 views

GPS 1 PPS Aligment Clock Signal Generator

i want to do GPS 1 pps aligment clock signal generator. Clock signal should be at 24.576 Mhz and voltage level Vmax= 3.3 V and Vmin=0 V DC. How can i do that? It is very important to align between GPS ...
0
votes
4answers
176 views

How to generate edge-triggered pulse

First, a bit of background: I am just a hobbyist with electronics and have very little formal education in the area. I understand most terminology, but generally require a schematic for me to be able ...
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3answers
199 views

Understanding Test Parameters on Datasheet (CL pF)

On Page 7 of the datasheet for M74HC590 It uses a CL (pF) At the bottom of Page 8 is the test circuit which shows where the CL(pF) goes, in regards to a circuit diagram, but I don't understand that ...
0
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0answers
71 views

Nixie Tube Clock Kit Issues

I recently purchased the Lena kit from Nixiekits.eu http://nixiekits.eu/Laura+Lars.htm The manual: http://nixiekits.eu/Downloads/USB_Nixie_Clocks_Aufbauanleitung.pdf After putting it together ...
4
votes
2answers
441 views

How to generate high frequency clock with high stability from a microcontroller?

I am using TivaC launchpad TM4C123G microcontroller, to generate a clock of 40 MHZ but I tested it on the oscilloscope and it doesn't look like a square wave it's more like a sinusoidal here is a ...
0
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0answers
71 views

I get error in vivado when I try to use source clock of generated one

I want to have two clocks in my project. One that sends output to a VGA and runs at 25 Mhz and another which runs my mandelbrot set calculation at a higher frequency. Here is the code I have. ...
0
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1answer
150 views

Output 48MHz system clock on a GPIO pin other than MCO pin on STM32F030

I want to output the max 48MHz clock signal of STM32F030 to drive another subcircuit. The problem is the chip STM32F030F4P6 (TSSOP-20 package) I prefer to use a GPIO because the MCU doesn't have the ...
4
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2answers
749 views

Can I produce a square wave(basically a clock) from a USB port on my Laptop? If yes how?

Can I produce a square wave(basically a clock) from a USB port on my Laptop? If yes how ? Briefly explaining, I am using ad9834 in a project and this chip needs a clock of any frequency ranging ...
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2answers
85 views

10 USB Hub ICs from 1 Crystal Oscillator?

I am designing a PCB with 10 individual USB hub ICs onboard. They all require a clock input and I am wondering if it is possible to drive all the clocks from a single crystal oscillator? The hub IC ...
0
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1answer
112 views

Strange ADC sampling frequency / clock frequency on STM32F401 board

I use a timer to trigger ADC sampling on STM32F401, and the interrupt service routine of ADC will toggle a GPIO pin so that I can measure the ADC sampling frequency using an oscilloscope (which should ...
0
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1answer
62 views

How to set SD card clock frequency between 100 kHz - 400 kHz

I am interfacing a 32 GB microSD card with PIC32MX795F512L. I am following the examples provided in Lucio de Jasio's book. As the author has described that to set a 250 kHz, they are ...
2
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0answers
43 views

Does sequential clock gating useful? [closed]

I know there is clock gating method that xor-ing the input and output of FF, and use that signal as clock enable. (figure 1, i'll call it xor-ing from now) I'm now studying sequential clock gating. I ...