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

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46 views

Which Clock Would Run Faster [on hold]

I have two identical clocks: one is plugged into 120 VAC @ 60 Hz. The other is running on a 12 volt battery. Which would run faster, and more importantly, WHY? Based on my understanding of a quartz ...
0
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1answer
30 views

How to calculate the oscillator capacitor value for a switched capacitor (MAX7405)?

I would like to use an 8-order LPF switched capacitor: MAX7405 datasheet The cut-off frequency can be set by simply connecting an external oscillator capacitor, Cosc. I would like to design a 50Hz ...
0
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1answer
74 views

Exact (accurate) and cheapest Second Signal Generator circuit

Sorry, this is my first question. I want to create a watch (clock) with needles, but I want to create a circuit to generate the second signal (not labview, not software). I need to know the IC's ...
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1answer
124 views

Is 'IF' statement necessary for the clock process?

I'm used to writing the following process that will react on the rising edge of the CLK (script 1): ...
1
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1answer
62 views

MPU accessing busy memory

I didn't know whether to place this question here or on stackoverflow, but I finally decided to post it here. I want to build a simple system that would be able to work with basic peripherals (UART, ...
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1answer
63 views

How can we find the clock frequency (SCK) set by master from slave in SPI

How can we (in software, no probing using CRO) know what clock frequency the Master applies from slave (assuming I have no prior information of this). In general I program the Div_Reg register and I ...
2
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3answers
55 views

Anyone have specific examples of how IEEE 1588 is most commonly used in industry?

I've run into the concept of IEEE 1588 synchronization over Ethernet several times, and am curious what its most common uses are and the details of why it is required. For example, I read that cell ...
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1answer
63 views

Improper functioning of Timer1 in pic18

I'm using pic18f controller and i am supposed to get a delay of 1 sec.I'm using an external crystal of 16mhz and this is the configuration bits that i have used in it.I have configured the timer1 and ...
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0answers
29 views

Parallel Write On External Clock on STM32

I am using 8 GPIO pins on an STM32F407 for a parallel write to an external device (FT232H). The parallel write is synchronous, ie. I have to synchronize my data to a clock provided. According to the ...
0
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1answer
44 views

For two clocked components in series, how do you ensure that the output of the first is captured by the second?

I'm working through the open Nand to Tetris course offered by Nissan and Schoken. I've just finished chapter 5, where we construct a 16-bit computer using a hardware description language and an ...
0
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2answers
53 views

What is the jitter of an asynchronous FIFO?

I have an asynchronous FIFO (in a Stratix V FPGA) with two asynchronous read and write clocks of the same frequency of 100 MHz. As I understand, asynchronous FIFOs have a two-register ...
1
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1answer
55 views

How to design a two-stage synchronizer with a clock divider in Verilog?

I have a very fast clock called CLOCK_50 which I would like to slow down through the use of a clock divider. The output is ...
0
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1answer
49 views

Why does `RCC_GetClocksFreq` return different results than I expect?

I have a STM32F427 MCU with a 8MHz HSE crystal. I am setting up the clock as follows: ...
5
votes
4answers
552 views

What is a ripple clock?

I am reading Chapter 12. Recommended Design Practices from the Quartus II Handbook Version 13.1 Volume 1: Design and Synthesis which states (p. 8): Ripple counters use cascaded registers, in which ...
0
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0answers
64 views

STM32 Timer Internal Clock Source

As I understand, the internal timer clock source on the STM32(F4) microcontrollers can be either APB1 or APB2. However, I can't find which timers get which clock. I already found ST AN4013, which ...
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1answer
51 views

Testing camera framerate variability by filming clock time

I would like to test the framerate variation from nominal value in a range of consumer video cameras. For this I intend to film some sort of high frequency clock and compare the displayed clock time ...
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2answers
93 views

does PIC16F628A has internal clock?

I'm reading tutorials about PIC16F628A, I found that in all project they use a Crystal Oscillator, is it means that the PIC doesn't any internal clock and it cant run without an external Crystal ...
2
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1answer
37 views

Setting up data prior to a rising edge - what's best practice?

I'm a newbie, playing around with a very simple single port block RAM (on an FPGA actually). Its 'read'-timing is standard stuff - i) An address on the RAM input gets latched on a first rising clock ...
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1answer
108 views

State switches in FSM

I have a simple board with 6 buttons, consisting of 3 columns and 2 rows I would like to detect the pressed button. My code below works with this fsm: ...
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1answer
64 views

Proper oscillator for CPLD

I plan to use KC5032A40 as a clock source for CoolRunnerXPLA3 256. I power it with 3.3V and interface it as suggested: I perform the measurement at the Test Point and do not add any CL capacitance, ...
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0answers
42 views

using the clock of FPGA in system generator

I have designed a circuit in system generator. I am using a FIFO at the output. I want to connect the we pin of FIFO to the clock of FPGA, but I do not know how should I do it in System Generator. In ...
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1answer
42 views

Best way to provide clock signals for a low input voltage charge pump

I would like to use a charge pump to step up a 1.5V AAA battery to >7V. The charge pump itself is already constructed and works fine when I test it with a 5V input. At this point I'm providing the ...
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0answers
111 views

Input pins in top module unconnected

I have a problem connecting different modules in a top module. I want to do a very simple PWM using a counter and a comparator. Counter: ...
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2answers
61 views

Usage of Next state and Clock Divider?

I have a clock divider and state machine like this: ...
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1answer
60 views

Signal Generation with duration in VHDL?

Im writing a signal generator in VHDL and I would like to set the duration of the signal generated to 75ms, it is an out signal and my clock is 100 MHz, I would be glad if you can help!
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2answers
104 views

Crystal Oscillator design with no data sheet

I am a newbie to circuit design and I need a 50MHz clock. I went to a local electronics store and got a 2-pin radial Quartz crystal. I do not have a data sheet for this. The only markings for the part ...
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2answers
64 views

Analyzing clock oscillator using timing diagram

In a recent examination a friend of mine was asked to analyze and find the frequency of oscillation of a clock oscillator using timing diagram as shown below: Can someone give me directions as how ...
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1answer
134 views

What are the functions of the ULN2003A and HCF4094 within this circuit?

We are building a wordclock and want to know what the following components do within the circuit: ULN2003A driver IC HCF4094 shift register This is the schematic:
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1answer
93 views

Enable clock for a state machine?

I have 100Mhz system clock and I would like to have a 200Hz Enable signal for enabling the state machine. I need a clock divider for this process and thought about this : ...
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2answers
420 views

What components are needed for a 20MHz square wave clock?

I would like to create a 20Mhz clock that generates a square wave for the home-brew Z80 computer I' making. I already have several 20MHz crystal oscillators but am at a loss when it comes to circuit ...
2
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1answer
85 views

Looking for 10GHz range clock generator

A bit of background: I'm doing some research with Doppler cooling and I need to design a new electronics package to tune a set of lasers to stimulate various two photon transitions. At the moment, ...
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1answer
56 views

defining base frequency, multiplier and divisor for dynamic clock manager

I am using a Spartan 6 xilinx FPGA, I managed to get it all working, changing the multiplier and divisor parameters at runtime. DCM_CLKGEN I use. My real oscillator is 66.6 MHz, but with PLL_BASE, I ...
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2answers
63 views

giving a lower clock rate to circuit in system generator [closed]

I want to give a lower clock rate to my circuit in System Generator. Can any one help me in this manner?
4
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4answers
142 views

Reconstructing Clock for Serial Signal

Suppose that I have a serial signal (example below), which is transmitted without an accompanying clock signal, I would like find a circuit (using discrete components / ICs, possibly an FPGA, but not ...
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1answer
112 views

Counting PIC18F46K20 internal clock edges using MPLAB C18?

I am trying to create a countdown timer using the PIC18F46K20 and display the time on the OLED. I have set up TIMER0 to create a delay of 1 second ( T0CON = 0b00000001 ) so the variabe intCLKsecs ...
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1answer
34 views

Quartus II Memory Read Clock Problem

I used LPM_RAM to store data and made read and write operations. But it seems like placing the data to wrong addresses. Here is screenshots; Wave Result; Memory Block;
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62 views

Do I need to use a programmable oscillator?

I can produce pwm signals with my mcu and I am intended to use this signal to feed another MCU's external clock input. But my output pwm signal voltage is 5V and I need peak to peak 2.5V signal and it ...
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114 views

How to use a crystal oscillator

I am trying to use a crystal oscillator as a clock signal for the PWMCLK input of a LED driver chip (TC62D723FNG) I have a FOX 1813-0245 8926 25.00000 MHz crystal oscillator I picked up at a local ...
0
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1answer
108 views

How to create variable clock frequency source in Cadence Virtuoso?

I am working on Delay Locked loop Project. I want to check the lock range of the dll. I am using vpulse for clock but by giving parameters clock period, clock width, rising time, falling time. It ...
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2answers
102 views

Clock synchronization between Cortex-A9 and Cortex-M3

I'm working on the synchronization between a Cortex-A9 and Cortex-M3 microcontroller. The Cortex-A9 is the master and is connected to the Cortex-M3 via SPI. How can the Cortex-A9 (master) and the ...
2
votes
1answer
74 views

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.
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1answer
69 views

Using the same clock for multiple shift register

Sorry for the beginner question. I'm working on a nixie tube clock and I have a bunch of shift registers for each tube. Do I need to use a different clock for each IC or can I use the same clock for ...
3
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2answers
152 views

How to “deserialize” a digital output to 4 digital outputs

I am working on a small test project for my Arduino and as part of it, I want to display a number on a 7-segment LED system. My first setup involved just direct links to the 7-segment display and ...
4
votes
3answers
745 views

Multiply clock frequency by three or more times?

Frequency of a digital clock signal can be doubled by using an EXOR gate (clock at one input pin and delayed clock at another). Can we use any similar circuit which can multiply frequency by three ...
2
votes
1answer
56 views

Eliminating Signal Race Hazard in an IC dynamic latch/register!

I work in MAGIC Integrated Circuit software at layout-level. I got an 8bit dynamic register made of 1bit dynamic flipflops that write input on the positive edge of the signal: (Note: I used ...
2
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0answers
93 views

How do I know if I fried my Z80?

I'm working on a free-running circuit like the one here: http://www.z80.info/z80test0.htm The only differences are that I'm using a 4049 clock circuit with a 1 uf cap, and I've added an extra LED at ...
2
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1answer
223 views

Johnson Counter VHDL

I have a problem given to me that states: Design a 4-bit Johnson counter and decoding for all eight states using just four flip-flops and eight gates. Your counter needs not be ...
3
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2answers
114 views

Clock Deskewing and flip flops

I have a question in my text book that I do not quite understand. I was wondering if someone could please explain what the question means? Such as, what is a deskewed flip flop. How would one find the ...
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1answer
47 views

Fixing ATtiny45 Clocksource

I accidently changed my ATtiny45 clock source to 128khz . After that I can't program it . I tried avrdude in terminal mode but it doesn't work . ...
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1answer
108 views

Crystals as RLC circuit? How?

What gives the crystal oscillator a property of Inductor? How does energy transformation between electrical field and mechanical stress and strain makes oscillator work like a Inductor? I know how ...