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My DFF FLIPs but it does not want to FLOP

[email protected] #90312 I hate cryptic error messages... Perhaps the author(s) of the program could add some possible solutions to solve the encountered errors?I ?I know I'm only dreaming. I just uploaded a zipped file. The schematic .asc and a .jpeg screen print of the displayed error. It's name is DFF ERRRRR.zip. Can any one telme what I do wrong? G.
Helmut Sennewald All Messages By This Member #90313 Hello, I don't see your file in the Files-section. Please upload it to this place below. Best regards, Helmut ? ?
Gunoi Nare #90314 The UPLOAD BUTTON is not working on this link. Clicking on it nothing happens. G toggle quoted message Show quoted text From: "helmutsennewald@... [LTspice]" To: LTspice@... Sent: Sunday, August 14, 2016 8:00 AM Subject: [LTspice] Re: My DFF FLIPs but it does not want to FLOP ? Hello, I don't see your file in the Files-section. Please upload it to this place below. Best regards, Helmut ? ?
Dave Wade All Messages By This Member #90316 Well I get an upload window on Windows/10 in IE, Chrome, Firefox and even Edge!. Are you signed into Yahoo with an account enrolled to the group? Dave From: LTspice@... [mailto:LTspice@...] Sent: 14 August 2016 12:06 To: LTspice@... Subject: Re: [LTspice] Re: My DFF FLIPs but it does not want to FLOP The UPLOAD BUTTON is not working on this link. Clicking on it nothing happens. G _____ From: "helmutsennewald@... [LTspice] <mailto:helmutsennewald@...%20[LTspice]> " <LTspice@... <mailto:LTspice@...> > To: LTspice@... <mailto:LTspice@...> Sent: Sunday, August 14, 2016 8:00 AM Subject: [LTspice] Re: My DFF FLIPs but it does not want to FLOP Hello, I don't see your file in the Files-section. Please upload it to this place below. <> Best regards, Helmut
Helmut Sennewald All Messages By This Member #90317 Hello, Flipflops require a value td or trise. Therefore right mouse click on the flipflop. A dialog window will pop-up. Enter the following in SpiceLine. td=5n See my uploaded example "DFF 1a.asc". ? One can add the options in line Value, Value2, SpiceLine, SpiceLine2. There are many more parameters for digital devices like Vhigh, Vlow, Ref, Trise, Tfall, Td .... Vhigh is the output high level, Ref is the input threshold voltage Please take a look to this example for the options. ? ?Best regards, Helmut ?
Gunoi Nare #90318 Thank you Helmut. but Again, What has to do the actual error with the displayed message and how shell I guess the connection . Do you see my point? G toggle quoted message Show quoted text From: "helmutsennewald@... [LTspice]" To: LTspice@... Sent: Sunday, August 14, 2016 8:00 AM Subject: [LTspice] Re: My DFF FLIPs but it does not want to FLOP ? Hello, I don't see your file in the Files-section. Please upload it to this place below. Best regards, Helmut ? ?
Helmut Sennewald All Messages By This Member #90319 Hello, The error message with your original circuit is caused by the missing td or trise. Td or Trise is required for flipflops. Unfortunately this is not mentioned in the help. Help -> Help Topics -> LTspice -> Circuit Elements -> A Special Functions Best regards, Helmut
Vlad All Messages By This Member #90323 > The error message with your original circuit is caused by the missing td or trise. Td or Trise is required for flipflops. Unfortunately this is not mentioned in the help. > > Help -> Help Topics -> LTspice -> Circuit Elements -> A Special Functions There is a passage there that mentions the state changes, but it refers to tripdt, not td, trise, tau or Rout/Cout: "The gates and Schmitt trigger devices supply no timestep information to the simulation engine by default. That is, they don't look when they are about to change state and make sure there's a timestep close to either side of the state change. The instance parameter tripdt can be set to stipulate a maximum timestep size the simulator takes across state changes." I think it's safe to say that the help is the least robust feature of LTspice, but maybe it's for the better: it makes you want to dig up for more. Or not. :-) Vlad ______________________ -- holding, among others: a universal analog/digital filter, block-level models for power electronics (and not only), math blocks with a more stream-lined approach, some digital ADC, DAC, (synchronous-)counter, JKflop, etc.

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