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

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2
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1answer
40 views

Switching tone on and off at 120 bpm not working

I am trying to make a design that toggles a sound at a rate of 120 BPM (once every .5 seconds), and I am using a 50 MHz clock. Here's the tone module: ...
0
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1answer
29 views

Access the internal clock on WLAN chips

I am trying to implement a localization method based on WLAN round trip time (RTT) ranging. Some of the papers I have read suggest doing ranging based on the MAC layer RTTs (beacons, ACK, RTS/CTS ...
0
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1answer
52 views

Crystal oscillator circuit

I am using following circuit and crystal is connected to XTAL2 and XTAL1 pin as shown below. Following IC is LPC2138, shown in image. I am using ADC chip ( DDC112 ) for A to D conversion. For ADC ...
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2answers
62 views

Taking the edge/ring off a clock signal with an RC circuit?

I'm designing a board for a hobby project where I am using a lattice machxo2 cpld as a system interconnect. The cpld needs to be clocked at 80-100MHz, and because I sprung for a cheaper cpld, it has ...
1
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2answers
77 views

Clock distribution gone wrong

I have had EMI problems in the past and I have decided to implement clock distribution with termination. I have a 25 MHz crystal that travels through a 50 \$\Omega\$ strip in the PCB and splits into ...
0
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1answer
32 views

ideal state of SPI MOSI and MISO pins?

Just wondering , If some how the MOSI and MISO tracks which connects the slave get cut. At that time, its disconnected from the slave. So if the micro controller tries to read data from MISO pin, ...
0
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0answers
36 views

24 Hour Counter JK Flip Flop

I'm trying to implement a 24 hour clock circuit using JK Flip Flops. I've gotten the minute part but I am having trouble designing the hours part, specifically the ones section. If it should count ...
0
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1answer
43 views

Spread spectrum 400 KHz

I got a 6-phase DC-DC converter. Fsw=400 kHz, synchronization by external clock(CPLD). I need a spread spectrum 400 kHz. What's the best way? All chips what I've seen before worked on MHz and above. ...
0
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1answer
41 views

Can SPI slave work with wrong clockphase setting?

In our prototype board, we have one 16-bit SPI based ADC [ad 7798] and an SPI based switch [adg1414]. Though some other guy has written the driver for it, and its also working. However when I ...
0
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2answers
65 views

“Clocking” and “Latching” with Arduino

I've just started using IC's, and am am trying to understand exactly how they work. I know that you must first clock in data to the shift register using Arduino's ...
0
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0answers
34 views

Kmap Implementation in Electronics Workbench

I'm working in Electronics Workbench and after simplifying two of the Kmaps, I got values : Jd=1 & Kd=1 How would I implement that in the circuit? I know it looks confusing at the moment.
0
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0answers
28 views

Limit amplitude and isolate impedance of a clock signal, without introducing noise

I am trying to drive the clock of a sequential logic circuit from a high-impedance input that receives a clock-like signal of somewhat variable nature from an external source. Input in practice may ...
0
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0answers
42 views

Continuous Wave with flip-flops

What I'm going for is imagine 6 LED outputs, every other one on. (Off first) What I need to have happen is after I toggle on the 1 input to 1, it sets off a chain reaction, like a wave, where every ...
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0answers
21 views

which is most preferred level,edge or pulse triggering? [duplicate]

Which is most preferred level,edge,or pulse triggering for Flip Flops?
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2answers
65 views

register without clk

I'm designing a small system in VHDL using the datapath and contorller method. Is it okay if I design registers that don't have a clock input (load data on the rising edge of the load signal) as they ...
0
votes
2answers
97 views

How to give clock on xilinx spartan 6?

I am trying to run a counter on Digilent Atlys Spartan 6 xc6slx45 development kit, which changes counts on clock edge. I am new user to Verilog, so I don't know how to give clock to my program from ...
3
votes
2answers
298 views

Clock generation on my PCB

I have not a big background in electronics. I am designing a PCB including a MCU (EFM32) and some ICs. I have seen in lots of circuits that they generally add an external Crystal Clock on the board ...
0
votes
1answer
123 views

Solid color display on VGA not working

I'm trying to get VGA working on my Altera DE0 board using Verilog, but haven't had much luck. It has the same pins as a normal VGA interface except red, green, and blue are all 4 bits each. Here is ...
0
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1answer
205 views

Why use STM32 HSE?

Why do we use an external oscillator for STM32??? Why not just use the microchip oscillator? I am using STM32F2xx it clocks at 120Mhz But, an external oscillator of 12Mhz is latch into the ...
1
vote
1answer
64 views

How do data and address strobes cause input to be latched?

Often in digital systems when multiple components communicate with each other they use strobe signals. Among these are data and address strobes. The strobe signal being asserted means that the data or ...
1
vote
1answer
121 views

I2C protocol debugging using oscilloscope

We are testing an I2C accelerometer connected to the ATMega32A micro-controller. The accelerometer was working fine. We can write and read the registers using I2C protocol. When connected to the ...
0
votes
1answer
92 views

Choosing between internal oscillator and external crystal- ATXMega32E5

We are working with a modern microcontroller ATXMega32E5, from the ATMEL XMega family. Our aim is to use the UART of the controller for effective communication, with the speed of about 9600 or 4800 ...
0
votes
1answer
83 views

How come the value in my RAM of DS1307 RTC become zero?

I'm using the 56 bytes of RAM in the DS1307 to store some data. My DS1307 is connected to the PIC18F46K22. But after running a few days, all the data inside the RAM will suddenly become zeros. The ...
1
vote
1answer
62 views

Verilog: sampling data in both posedge and negedge of the clock

I have a serial input stream which has left data in posedge of the clock, and right data in negedge of the clock. I would like to synchronize and bring them to the posedge of the same clock. I could ...
1
vote
1answer
58 views

Delete or ignore I/O from a schematic block in Lattice?

I am programming with a Lattice ispMACH 4000ZE Pico DevKit and with the software ispLEVER Classic Project Navigator. I want to use in my schematic file the OSCTIMER block from the Lattice library, but ...
0
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0answers
34 views

Wave generator for a certain clock pattern

Refer to the figure above. How can I generate these clock patterns? What waveform generator should I use? I have used this lately (refer to figure below): And my clock patterns are these:
1
vote
1answer
76 views

Assembly XMEGA program creating a longer than expected pin toggle?

I'm trying to do the fastest pin toggle possible on an XMEGA32E5 running at 32MHz. My code is as follows: ...
1
vote
1answer
54 views

Cable for transmitting 4MHz 3V3 signal

I am building a device on breadboard where there are 2 ICs: a microcontroller and some auxillary IC, they should communicate via SPI with a 4 MHz clock. Because I don't have enough place on my ...
0
votes
2answers
66 views

How can an input signal to an FPGA be determined as the clock signal?

How can I determine a seemingly arbitrary signal applied to an FPGA to be the clock signal? Conditions: 1. There is no other clock signal available (as an input to the FPGA) for sampling this input.2. ...
1
vote
2answers
419 views

Porting SPI code from (Intel) Galileo to Edison - Arduino

I'm currently working to port some Arduino sketches from Intel Galileo that use SPI (using a prototype Arduino Breakout board). I haven't been able to get it to work so far - but I have used an ...
0
votes
1answer
86 views

Why do we need Frequency Divider for external clock (GPS reference signal) for Frequency Counter?

Our senior project is to build a precision frequency counter which is using GPS signal as a reference. I looked up somebody else project online and found that I have to divide reference signal ...
0
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0answers
69 views

Feed Raspberry Pi camera module with external clock signal

I want to frame synchronize multiple Raspberry Pi camera modules - I guess I can do this by feeding all the modules with a single external clock signal. The thing is being discussed in this post. The ...
0
votes
1answer
195 views

Custom built 16x32 (40) LED Matrix controlled by Arduino

I am planning to build a clock / thermometer / info display. I have ordered 10 pieces of 8x8 LED matrixes from ebay (http://www.ebay.co.uk/itm/331064583297). As this is not a pre-built one I have got ...
0
votes
2answers
63 views

Building a first State Machine circuit - Technical Help

I just learned how to synthesize a diagram of a finite state machine into a diagram of a logical circuit composed of D flip flops, a clock and logical gates. However, I don't really have much ...
0
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1answer
226 views

50 MHz FPGA (Cyclone IV @ DE0-Nano) and 60 MHz input from FT2232H

I want to read data from FT2232H used in an FT245 style synchronous FIFO mode (http://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT2232H.pdf p.27) with DE0-Nano FPGA board: ...
0
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0answers
45 views

Pipeline Processor Calculation

My assignment deals with calculations of pipelined CPU and single cycle CPU clock rates. The following data is given, about the time each operation takes to execute: ...
2
votes
3answers
61 views

Interpreting Crystal Deviations

I am investigating the accuracy of a crystal mounted on a MCU. The API provided by the MCU manufacturer has a TimeGet48 function that returns a 48-bit number ...
2
votes
1answer
93 views

Clock Ringing/Noise

I'm trying to make a simple 32.768kHz clock circuit. On the datasheet for a crystal that I found, it included the following circuit: simulate this circuit – Schematic created using ...
0
votes
1answer
60 views

Clock / timer activated 2 second voltage timer for wiper motor project

Ok, I need a 12 volt voltage timer using clock or timer for a wiper motor. I am working on a project in my garage. Simply put, I am wanting to use a wiper motor that will open and close a spring held ...
1
vote
1answer
143 views

counter that MSB toggles every 2 seconds [duplicate]

I want a counter that the Most significant bit toggles every 2 seconds, and gets values 0 and 1.So for example it will have 0 for 2 seconds and after 1 for another 2 seconds etc.. I need it like that ...
1
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0answers
184 views

Atmega32 can't verify after setting correct fuses for external crystal. HELP

I am having trouble with some Atmega32A's purchased off from eBay. The MCU's does not seem to be fake as they are functioning properly. I am experiencig the following problem: I want to use external ...
5
votes
2answers
330 views

How do IC's know when there is a downward or upward transition of a clock pulse?

Title pretty much says it all. But how do most IC's, micro-controllers, etc. know when a clock cycle starts a downward or upward transition from the clock source?
2
votes
1answer
73 views

CPU and clock rate

As I understand it, CPUs generate electrical pulses using a quartz crystal. The rate the pulses are generated (taking into account various multipliers) give the processing speed which all components ...
1
vote
1answer
71 views

Do I need to reset a DDR's DLL when I change clock frequencies?

I have a system that boots at one frequency and then the main PLL is reloaded to continue boot at a higher frequency. When this is done, the DDR is put in to self refresh. After the main PLL locks, ...
0
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0answers
83 views

How to convert square output of Si5351 to sawtooth when working at 28.8 MHz

I'm going to build a clock generator around the Si5351A chip. The configured output frequency will be 28.8 MHz. The output of the chip can only be a square wave. I've seen some schematics on the web ...
1
vote
1answer
407 views

Genlock two OV5642 camera modules on Arduino with ArduCam

I need to shoot stereo video or stills at about 10 FPS possibly in perfect sync. My plan is to set up a 3D stereo rig (2 standalone units - each consisting of Arduino UNO + ArduCam shield + OV5642 ...
0
votes
1answer
42 views

Controlling the frequency of oscillation of SI530 VCXO

I am thinking of using the SI530 VCXO as a means to generate clock signal at frequency of 1.4 GHz. But in the datasheet I do not pin which controls the frequency of oscillation. Can someone help! ...
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0answers
53 views

Frequency locked loop for input jitter rejection

I have an application where I want to multiply from a xtal oscillator at 32KHz to a system clock of 40MHz. A standard PLL isn't going to do the job, because the 32KHz jitter is measured in ns. Since ...
-1
votes
1answer
59 views

Which Clock Would Run Faster [closed]

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
votes
1answer
48 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 ...