The clock-speed tag has no wiki summary.
1
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3answers
94 views
Making a clock spin faster
I'm pretty new to electronics and hope that this is the right place to post this. I want to take a battery powered analogue clock and make the hour and minutes hands spin faster. I want to make it ...
1
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2answers
89 views
Pipeline question
I'm having trouble with this question.
Assume a 5-stage pipeline and a 200 picosecond clock time.
what is the time required to execute one instruction?
assuming the pipe is kept full, ...
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0answers
44 views
Measuring CC2420 clock
I'd like to measure the CC2420 clock on a TelosB module that includes a MSP430F1611 microcontroller running the Contiki OS. I turned the CCA pin into a test pin to output the radio's 8 MHz clock. The ...
5
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2answers
327 views
AVR interrupt service routine not executing as fast as expected (instruction overhead?)
I'm developing a small logic analyzer with 7 inputs. My target device is an ATmega168 with a 20MHz clock rate. To detect logic changes I use pin change interrupts. ...
3
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3answers
1k views
“Overclocking” an AVR
In AVR datasheets under the Electrical Characteristics section you will typically find a graph like this (this one is from the ATMega328):
I've seen designs that seem to "work" but operate outside ...
3
votes
1answer
236 views
How can a CPU dynamically change its clock frequency?
My Intel CPU changes clock speed depending on the usage, but how does it decide what clock speed to run at? Is the clock speed determined by the OS software using an algorithm, or is it hardware ...
2
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1answer
141 views
Determine suitable clock speed?
I want to learn about good techniques on how to choose the suitable clock speed for the microcontroller for a project.
For example i want to create a device with a pic16f877 microcontroller that ...
2
votes
1answer
78 views
Limitation of baud due to propagation of voltage over distance
I need to make sure I have my facts straight here; the math works but I may be missing something:
In a 100BaseTX network over Cat-5 copper, each party has a circuit (one twisted pair) on which they ...
5
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3answers
462 views
PIC problem: Touching the crystal capacitor makes the system slows down
I am experiencing a very unusual problem (at least for me). When I touch with my fingers, or the oscilloscope probes, on the crystal or it's capacitors, the PIC runs slower...and A LOT slower then it ...
3
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4answers
296 views
Can't run PIC24EP128MC206 at rated speed
I got a PIC24EP128MC206 because of its rated speed of 70 MIPS. (For whatever reason, it is rated in MIPS, while most other PIC24s are rated in MHz.)
Since my understanding is that one instruction on ...
8
votes
1answer
167 views
Is a 10GHz clock required to drive a 10Gb serial pin?
I am reading about the 10Gb/s Ethernet PHY for Altera FPGAs (datasheet here). I was impressed to know that, at the hardware level, the 10Gb/s is done serially.
Naively, I would think to do 10Gb/s ...
3
votes
1answer
177 views
Clock skew? Good or bad?
So, I've been reading up on clock skew. I came across the fact that clock skew can be incredibly useful, in the sense that positive skew can be used to speed up the circuit by increasing the clock's ...
2
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1answer
864 views
Multiplex Seven Segment Display Fast enough to make Solid
I have been trying to multiplex a 4 digit seven segment display on my FPGA board but have been running into not being to get it fast enough so it looks solid to the human eye.
You can see an example ...
4
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4answers
407 views
Increase Microcontroller frequency and Speed
I am in process of upgrading the micro-controller of our project from Renesas M16C to RX63N. In our current M16C project we use 16HMz crystal. If in the new micro-controller Rx63N if I use the ...
2
votes
2answers
198 views
Clarification on what the max freq of PIC24FJ64 is?
I'm confusing myself a bit here. The following is taken from this datasheet:
High-Performance CPU:
Modified Harvard Architecture
Up to 16 MIPS Operation @ 32 MHz
Now I want 16 MIPS, which is its ...
10
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6answers
5k views
How do I set the clock speed fuses on an ATtiny85 when using an Arduino as a programmer?
I'm following this tutorial, programming the ATtiny85 with an Arduino, using it to play some tones (through a piezo speaker). I'm struggling with getting the tones at the right pitch (I'm creating the ...
14
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1answer
1k views
Why do Arduinos ship w/ 16MHz crystal instead of 20MHz?
Why do Arduino boards ship w/ 16MHz crystal instead of 20MHz? They are spec'ed for operating at 20MHz, after all.
I guess there are a few advantages to running more slowly (lower power consumption, ...
2
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1answer
160 views
What is my AHB1 clock rate?
I am working with an ARM Cortex M3 chip (reference manual available here). I'm trying to get the baud rate of my USART communications right. Reading pages 613 onwards, I understand that the value I ...
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2answers
1k views
ADC sampling rate to MCU clock speed relationship
How can I determine the clock speed requirements of a mCU to manage a given ADC input?
This application is very simple - I just want to take an SPI stream from an ADC into a mCU and spit it out the ...
7
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3answers
2k views
Can faster processors/clocks execute more code?
I am writing a program to run on an ATmega 328 which runs at 16Mhz (its an Arduino Duemilanove if you know them, it's an AVR chip).
I have an interrupt process running every 100 microseconds. It's ...
0
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1answer
164 views
bit bang programming with a 1/222.2ns clock
I need to bit bang at a 1/222.2ns clock rate.
I am looking a recommendation for the bit banging clock source and "easy" to program means of bit banging at this clock rate.
4
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5answers
561 views
Does anyone know of a microcontroller/DSP with no clock speeds or any oscillators in excess of 1.705 MHz?
I am planning on making a simple electronic device which I might eventually try to market if it works out O.K. Before taking the plunge and trying to mass produce it, I would first try to sell a few ...
2
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2answers
4k views
How do I calculate needed pixel clock frequency?
If I want to have a resolution of X * Y pixels, updating in frequency f. How do I calculate the pixel clock speed?
Example:
1280 x 1024 @ 85Hz usually have a pixel clock of 157.5 MHz, but how do I ...
