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

learn more… | top users | synonyms

0
votes
1answer
39 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
votes
1answer
38 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
votes
2answers
49 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
votes
0answers
31 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
votes
0answers
27 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
votes
0answers
40 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 ...
0
votes
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?
1
vote
2answers
63 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
59 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
293 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
98 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
votes
1answer
148 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
51 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
112 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
74 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
64 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
55 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
49 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
votes
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
64 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
51 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
64 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
344 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
77 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
votes
0answers
55 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
179 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
59 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
votes
1answer
196 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
votes
0answers
42 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
90 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
49 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
140 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
vote
0answers
149 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
327 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
71 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
62 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
votes
0answers
62 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
347 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
40 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! ...
1
vote
0answers
50 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
45 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
votes
1answer
99 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 ...
1
vote
1answer
163 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
vote
1answer
75 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, ...
-3
votes
1answer
94 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
votes
3answers
59 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 ...
-1
votes
1answer
106 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 ...
0
votes
0answers
57 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 ...