Hasnt Lopez technically achieved metastability?
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πŸ‘€︎ u/Etrixik
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Verilog metastability issue
always @(posedge clk_50MHz)  A <= (A > 10) ? 1'b1 : 1'b0; 
always @(posedge clk_350MHz)  
begin     
    B <= A;     
    D <= ~B && A; 
end

Both clk_50MHz and clk_350MHz are generated from the same PLL and have the same phase shift.
Would the code snippet above generate any issues such as metastability, etc ?

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πŸ‘€︎ u/promach
πŸ“…︎ Nov 14 2021
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Metastability and debounce logic

I have slow asyncronous signal on one of my fpga inputs, that need debouncing. And i have code that handles this issue:

logic [31:0] debounceCount;
localparam updatePer = freq/10;
always @(posedge clk) begin
if (in^out) debounceCount <= debounceCount-1;
else debounceCount <= updatePer;
if (~|debounceCount) out <= in;
end

Should i add syncronizer logic to evade metastability on signal "in" or code i have will be enough?

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πŸ‘€︎ u/Top_Carpet966
πŸ“…︎ Nov 30 2021
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Need help with clocking in my CPLD code - TB waveform does not match real-world test. I think I'm running into metastability when crossing domains

I'm new to verilog, and I'm essentially teaching myself as I put together this proof of concept for a work project (sole designer, we usually operate in the mcu space but needed a cpld for regulatory reasons here). Short summary is the device is waiting for a dropped signal (nOutageDetect = 0) and will trigger a pair of relays to open and close after a 5s delay. when the signal returns (nOutageDetect = 1) the relays should switch after another 5s delay.

The TB waveform shows that this is happening exactly as designed, but when I try to reproduce it on my prototype test bed the delay stretches out to minutes.

source code:

`timescale 1ps/1ps

module prototype
(relayPos, nOutageDetect, capGood, openRelay, shutRelay, xferSwitch, plugType, manualOverride, LED_utilityPower, LED_dcMonitor, LED_0, LED_1, LED_2, gclk);

input wire relayPos;					// 0 = relay closed		1 = relay open
input wire nOutageDetect;				// 0 = signal lost  	1 = normal
input wire capGood;						// 0 = not charged 		1 = charged &gt;14v
input wire plugType;					// 0 = add-on missing	1 = add-on connected
input wire gclk;
input wire manualOverride;

output reg LED_utilityPower = 1;
output reg LED_dcMonitor = 0;
output reg xferSwitch;					// switches secondary relay
output LED_0, LED_1, LED_2;				// LEDs programmed for demo debugging. utility likely to change
output reg openRelay = 0;               // trigger to open primary relay
output reg shutRelay = 0;               // trigger to shut primary relay

//pragma attribute LED_dcMonitor    	pinnum 4
//pragma attribute LED_utilityPower     pinnum 6
//pragma attribute LED_dcOverride   	pinnum 9
//pragma attribute manualOverride   	pinnum 40
//pragma attribute plugType 		    pinnum 5
//pragma attribute xferMonitor 		    pinnum 8
//pragma attribute nOutageDetect    	pinnum 20
//pragma attribute capGood		    	pinnum 34
//pragma attribute relayPos 		    pinnum 11
//pragma attribute shutRelay 		    pinnum 16
//pragma attribute openRelay 		    pinnum 14
//pragma attribute xferSwitch	    	pinnum 39
//pragma attribute gclk 		    	pinnum 43
//pragma attribute LED_0		    	pinnum 12
//pragma attribute LED_1		    	pinnum 17
//pragma attribute LED_2		    	pinnum 18

wire [2:0] LED;
assign {LED_2, LED_1, LED_0} = LED;

//////////////////////////////////////////////////
//
//	clocking block - 32kHz
... keep reading on reddit ➑

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πŸ‘€︎ u/Sage2050
πŸ“…︎ Sep 30 2021
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How does the Higgs Boson and top quark mass help us infer the stability/metastability of the universe?

I'm just an aficionado so try to keep it dumbed down please!

All articles I've seen state that the mass of the Higgs and the top quark seem to be on the limit between stability and metastability, although it still hasn't been confirmed. My question is not regarding in which state the universe is but why does this measurements relate to it. Why does it mean than if the masses of these particles was different then the universe will be in another estate of stability/instability/metaestability/non-perturbability?

In short, where do the regions of this chart come from and why are they there?

Also, what does the non-perturbability region mean?

Thanks!

EDIT: I see lots of shadow banned people here.

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πŸ‘€︎ u/Maezel
πŸ“…︎ Sep 23 2020
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"Breaking metastability in Tangle Multiverse using shared perception of voting weights" by Ioda

https://iota.cafe/t/breaking-metastability-in-tangle-multiverse-using-shared-perception-of-voting-weights/1207

This is an interesting new post on iota.cafe about the Multiverse proposal and its viability 🦾

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πŸ‘€︎ u/quantengeist
πŸ“…︎ Mar 09 2021
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27 [F4A] Of Metastability, Free Energy, and Driving Force

In life where the only constant thing is change, will you prefer to stick in one place or let yourself be carried away? What pushes you to move forward? In what direction do you want to be lead on?

Eme lang, pa-deep ang lola nyo. Lezz chat naman. Kasabawan talks lamang.

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πŸ‘€︎ u/hakdawg
πŸ“…︎ Jul 01 2021
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Metastability and Distributed Systems brooker.co.za/blog/2021/0…
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πŸ‘€︎ u/alexeyr
πŸ“…︎ Jun 14 2021
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Sanity question on synchronizing single pulse, metastability, and twice frequency.

I had always thought this was safe, but now reading this classic Cummings Sunburst paper on metastability, I'm getting paranoid.

I have clk_source = 100 MHz, clk_destination = 200 MHz. Clocks are not synchronous to each other. Both are 50/50 duty cycle. Assume rising edge captured flops only.

Say I have a pulse signal generated in clk_source domain that is 1 cycle wide, so 10ns wide. Pulses are not back to back and instead spread out from each other by say 20 cycles.

Shouldn't I be able to use a "double flop synchronizer" that is clocked in clk_destination domain to reliably guarantee capture of these pulses to this domain?

The clock is twice the frequency and I thought this satisfied some Nyquist rate. Drawing it out, I can't see a case where at least one clock edge of the clk_destination would reliably sample the pulse. There isn't a case I see where the pulse would be completely missed. Is there a case in this scenario where the pulse could possibly be missed?

Ignoring any arguments about MTBF not being completely 0 for a double flop synchronizer, as in a correct usage case, the synchronizer will reduce down to some acceptable level like 99.99%.

EDIT: The section causing me to doubt myself is 4.1.1 where it states "input data values must be stable for three destination clock edges."

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πŸ‘€︎ u/prana_fish
πŸ“…︎ Sep 28 2020
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Girls Own the Void: Trans Women, Alienation, and Metastability youtube.com/watch?v=5Abzh…
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πŸ‘€︎ u/table_knife
πŸ“…︎ Feb 27 2021
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Metastability question and capturing pulses across clock domains.

Hi.

I had a question in understanding how metastability can result in missing a captured pulse. There are multiple ways to capture pulses across domains, but for the sake of this question, just assume I'm edge detecting.

I have a fast clock at 100 MHz that has data pulses separated by a number of fast clock cycles. I want to capture every event of this pulse in an asynchronous slow clock domain of 50 MHz (half speed). The original fast clock pulse is stretched to be 3x wide to ensure after it goes through a double flop synchronizer, it will be sampled at least once in the slow domain.

As long as there is sufficient cycles between assertions of the stretched fast clock pulse, the slow clock domain should capture them all.

However I'm drawing out a cornercase to show how one assumption of "sufficient cycles between assertions" will not hold true and I think can cause missing a pulse.

This picture_A here shows that clock edge 2 when violating setup time when the Din transitions too closely, the latency through the synchronizer is 2 cycles and both original fast clock cycles are replicated in the slow clock domain.

This picture_B here shows that clock edge 2 when violating setup time, now instead the latency through the synchronizer at this point takes 3 cycles. So I "think" this means that since the first flop in the double flop synchronizer goes metastable, it will not resolve in time to correctly capture at clock edge 3 the low sample, despite the fact that the low sample at this point is completely stable.

Is this correct? So when the first flop goes metastable, the next rising clock edge of a stable Din value will not register in some cases?

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πŸ‘€︎ u/someonesaymoney
πŸ“…︎ Nov 01 2020
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My MIL passed away last thursday. She lost her 5 months fight to an aggressive stage 4 (metastic) liver cancer. This is her last image walking, smiling and happy.
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πŸ‘€︎ u/dicavalcante
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Lopez has reach metastability hasn't he?

After watching the last season of RvB, we now know Lopez has more than enough time to reach that state and considering Lopez has show sign of sentient since early on. Lopez had shown more human like nature as the show goes own plus the fact that he's literally older than Chrovos/Genkins himself since he fall into the black hole before him, learn the truth of the universe (and probably already become a god too by the current time), the chance he is not already metastable is nearly 0.

i hope the next season Lopez will truly be meta stable.

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πŸ‘€︎ u/Hexxerald
πŸ“…︎ Apr 21 2020
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Unequivocally speaking, is low-power mode the definitive explanation from Outpost Discovery that smart AIs can live past 7 years? If so, why didn't more AIs do it? What of metastability (that smart AIs can be truly human after enduring rampancy)?

Examples:

-Solipsil (2530-50)

-Deep Winter (2541-51)

-Kusanagi (2535-52)

-Kalmiya (2537-52)

Just those four.

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πŸ‘€︎ u/ALDO113A
πŸ“…︎ Apr 26 2020
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A solution to metastability in VHDL

Hi! I thought I'd post this here because some of you might have encountered this problem in your own projects.

In short: Metastability is a situation where a flip-flop circuit gets stuck between 1 and 0 on certain inputs for an indefinite amount of time.

There is a good Wikipedia article about it, which tells you more about the problem:

https://en.wikipedia.org/wiki/Metastability_(electronics)

I've solved this problem by placing a "deoscillator" to the circuit, which stops it from looping between 1 and 0.

My solution and more details about the solution can be found here:

https://gitlab.com/eronenveeti174/deoscillated-flip-flop-in-vhdl/

This was originally developed as a part of a failed start-up endeavour, but now it's published with Creative Commons Zero license which means it's public domain and free for anyone to use for whatever purpose they see fit.

If someone has any idea how to publish this solution more widely I'm open to all suggestions.

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πŸ‘€︎ u/eronenveeti174
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This meme is like Sigma's metastability pattern
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πŸ‘€︎ u/averagejoey2000
πŸ“…︎ Feb 27 2019
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TIL that if our universe is part of a metastable (false) vacuum then a vacuum metastability event could occur and destroy all that we know without forewarning. en.wikipedia.org/wiki/Fal…
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πŸ‘€︎ u/PantsofJoy
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Unequivocally speaking, is low-power mode the definitive explanation from Outpost Discovery that smart AIs can live past 7 years? If so, why didn't more AIs do it? What of metastability (that smart AIs can be truly human after enduring rampancy)? /r/HaloStory/comments/g84…
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πŸ‘€︎ u/ALDO113A
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TIL that the Universe may exist in a false vacuum. If it dropped to a lower energy state in a vacuum metastability event, a true vacuum bubble could form in our Universe, endlessly expanding at light speed and annihilating everything in its volume. Thus, all we know may cease to exist in an instant. askamathematician.com/201…
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πŸ‘€︎ u/D3v1ous
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[journal] Dissipative quantum state preparation and metastability in two-photon micromasers journals.aps.org/pra/abst…
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πŸ‘€︎ u/iciq
πŸ“…︎ Apr 29 2020
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Metastic hepastatic
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πŸ‘€︎ u/CSP_17
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Is there a reliable way to calculate how long it took for a double flop synchronizer to resolve metastability?

Say have an external async signal coming straight from an IO pad into a double flop synchronizer. So have:

async input --&gt; D1 --&gt; Q1 --&gt; D2 --&gt; Q2 --&gt; output

where Q2 is the final safe and stable value (let's not bring in MTBF failing here).

If you have 3 total clock cycles, the output of the synchronizer Q2 can resolve to the value you want either in clock cycle 2 or 3. So there is an indeterminism of 1 cycle here.

Is there a way to calculate after the fact based on Q2 how long it took to resolve? I can't use a difference between Q2 and "async input" as async input is unstable.

Note: I'm not trying to synchronize multlple bits passing each through it's own double flop synchronizer.

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πŸ‘€︎ u/someonesaymoney
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Just found out my grandma has stage 4 Metastic BC.

My grandma and grandpa have raised me since I was 5 months old. I am now 35 and still live with them and help take care of the lawn and house and drive them places far off when they need to go. Today my grandma found out she has stage 4 breast cancer. She won't tell me how long the doctors gave her. I am a wreck today. I work from home for a call center at night and I am currently crying in between calls. This hurts so bad. I honestly can't imagine life without her. Every time I look at her now I get a lump in my throat and a nausious feeling. I love her so much but I feel awkward around her now because she is in so much pain. She still gets around well and drives, but she is rapidly losing weight and is refusing any and all treatment besides stuff to make her comfortable. I am single with no children or girlfriend and my grandparents are my life. I guess death is just a part of life. Can anyone give me any advice on how to deal with this? Will therapy help? I can't even look at family photos on the wall right now without crying. I just needed someone to vent to. Can anyone tell me what to expect and maybe how to deal with it better? I am so depressed I can't stand it and can't stop thinking about it.

Just needed to vent I suppose.

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πŸ‘€︎ u/roamifyouwant2
πŸ“…︎ Dec 11 2021
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what is the probability that a vacuum metastability event occurs inside my body? i’m 5’6” and 63kg (so you guys can figure out my volume)
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πŸ“…︎ Dec 20 2017
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STUPID IDEA: If you think about it, electrons and atoms are similar to the Meta and the metastability idea. Similar to the way that the Alpha AI fragments wanted to become human by joining together, atoms want to become Noble Gases by taking electrons from other atoms. This is kinda shown with Na+Cl
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πŸ‘€︎ u/rogerthat81700
πŸ“…︎ Nov 26 2018
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metastability for a slow, imprecise signal

lets say i have some form of alarm signal that will be asserted and then remain high for a very long time. do i have to worry about metastability at all? i mean it may fluctuate for a few clock cycles, that would be ok, but it will after a few cycles be set to high, won't it? if i have such a signal i can just ignore clock edges.

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πŸ‘€︎ u/bunky_bunk
πŸ“…︎ Aug 03 2018
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COBRA - Vacuum Metastability Event 2012portal.blogspot.co.nz…
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πŸ‘€︎ u/wozzels
πŸ“…︎ Jun 13 2017
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Any idea as to the Metastability mentor Eric ? that terence refers to in this lecture? youtu.be/by3HmipUVrc?t=34…
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πŸ‘€︎ u/JSIN33
πŸ“…︎ Aug 24 2016
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Measurements of the mass of the Higgs boson seem to indicate the vacuum is metastable?

I read in an article about false vacuum in space that "measurements of the mass of the Higgs boson seem to indicate the vacuum is metastable".

Can someone please explain this?!

How does the mass of HiggsB indicate the vacuum is metastable and not stable or unstable?

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πŸ‘€︎ u/omgsoftcats
πŸ“…︎ Dec 16 2021
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Metastability Question: Interfacing AVR clk with another device

In the project I am currently working on, I will be interfacing an AVR to an FPGA. Specifically, I will be sending the FPGA data via the AVR's SPI interface. I would also like to use the external clock pin of the AVR to drive the FPGA digital logic, and avoid using the FPGA's internal oscillator.

Question: Since the AVR's SPI clock is derived from the same clock used to generate the external clock pin, will I have to worry about taking any special precautions to avoid metastability issues? In other words, although they are different speeds, are they still considered to be within the same clock domain?

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πŸ‘€︎ u/coldcoffeecup
πŸ“…︎ Mar 10 2015
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A new understanding of metastability clears path for next-generation materials sciencedaily.com/releases…
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πŸ‘€︎ u/Erik_Feder
πŸ“…︎ Nov 21 2016
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How does an AI achieve metastability?

After the announcement of Halo Wars 2, people were debating when it would take place. People where saying a couple years after the events of Halo Wars and others were saying the year 2558, or the present Halo universe. Many people have made theories as to what's going on, where the trailer takes place, but people sometimes talk about Serina, the AI on the Spirit of Fire in Halo Wars when discussing these topics. If the game did take place only a little while, say 0-5 years after Halo Wars, Serina would be going rampant. However, if Halo Wars 2 does take place in the present Halo universe, the only way Serina would have survived is by achieving metastability. So I have put this question on waypoint and now I go to reddit. So my question is, how does an AI achive metastability?

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πŸ‘€︎ u/reachguy117
πŸ“…︎ Aug 06 2015
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AMA WITH AVA - Scalable and Probabilistic Leaderless BFT Consensus through Metastability - A must watch! youtube.com/watch?v=tavO6…
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πŸ‘€︎ u/fawkesss81
πŸ“…︎ May 30 2019
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πŸ‘€︎ u/Balance-
πŸ“…︎ Sep 27 2018
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Peter Alfke (Xilinx) explains why metastability often wrongly gets the blame in FPGA designs groups.google.com/group/c…
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πŸ‘€︎ u/Milumet
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