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Hold Time And Setup Time

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333 Threads found on edaboard.com: Hold Time And Setup Time
hi friends how can i design a D flip flop and calculate setup and hold time for it? Is there possible design d flip flop with PSSL family of logic ? thanks in advanced
Hi, I would like to know how does clock latency affect setup and hold time? Does it help in any way?
Hi, I'm just referring a processor is a 33MHz rated part. The AC Characteristics for 33MHz part tell CLK can be from 8MHz to 33MHz and is further specifying databus setup time as 5ns minimum. I have doubt if i provide the processor with 12MHz clock will the setup time (...)
Hello, I am about to find the setup time value for Virtex-5 FPGA (XC5VLX50T) and have looked at page 45 of the following datasheet: it provides lots of timing values except the setup time value !! I know that hold (...)
Hello all , There are times, when I am not allowed to change the RTL, and all the clocking structure in the design are already optimized. Still I face situations where I have negative slack ( setup as well as hold ) Some times by trying few strategies in Vivado, the (...)
if you have a path where two registers use the same clock enable that is a periodic clock enable, then you know that the setup and hold time can be much longer for these registers as they really only get updated once every N clocks.
dear all, if i have 2 flip-flops , ff1 clock pin is connected to clk ff2 clock pin is connected to gated clock..... my doubt... if i found either hold r setup violation on this path with repsect to +ve edge.. then how i can fix the violation can any one guide me thanks in advance bhaskarg
The set up and hold times of a FF are function of clock transition time and input transition times. What is the relation actually?? It seems the setup and hold (...)
Hi. As I know basically, in synthesis, we can get the information which is WNS,TNS, from start point to end point critical data path from synthesis schematic. Also mostly in initial synthesis, we focus/concentrate on the setup violation because the hold violation is changed from CTS flow and P&R flow. But I'm confused that the effect (...)
If setup and hold times exceed designed wait times, errors can occur. But this is only one of a dozen or more mechanisms that can influence SNR and BER. Many different algorithms to determine optimal settings or reliability have different tradeoffs for (...)
Hi How crosstalk impact the values of setup and hold time ?
At first sight, it looks like a trivial setup or hold time violation. Did you check with setting d earlier and holding it longer?
Hi, A Flip Flop is made up of master latch and a slave latch. setup time: We need to provide enough time for the input capacitance of Master latch to be charged up or discharged down, before the Master latch captures the data. To ensure that this happens ,we have a setup (...)
Yes, both setup & hold violations are possible in the same path. setup analysis will be done in the slow corner, where as hold is done in the fast corner. Now, look at this way, the combo path consists of only HVT cells ( which usually gives more delay in slow corner, less delay in fast corner ). This is due to delay (...)
Hello all, Suppose I am having a D flip flop. Now what are the parameters those affects the setup and hold time of the same? If I want to change it, how to change it?
check this link Fixing setup & hold Violations
Hi I saw CPPR adjustment is added in the setup path and subtracted in the hold timing. What is the Purpose of CPPR. and hold time is calculated at the same edge of clock at two flipflops... so if a hold violation occurs then there is a possibility (...)
Memory cells, FF's or any edge sensitive logic must have a setup and hold time must have data stable for this amount when the worst case clock skew edge occurs. This is a standard requirement for synchronous logic. Otherwise for asynch logic, race co
What is the difference between Timing analysis done in Design Compiler , Prime time and ICC Compiler. Which tool is preferred ? How do we fix setup & hold violations using Design Compiler ? Post Synthesis (library.db and gatenetlist.v are given as I/P to (...)
Probably a misunderstanding of SPI operation. SPI is designed to have setup and hold time of about 1/2 clock cycle by launching data at one clock edge and sampling it at the other edge. In so far, a 10 MHz SPI interface doesn't require any particular precautions (...)
Hi all, Why static timing analysis is not efficient for asynchronous designs..please explain . Thanks Asynchronous logic is more efficient in complexity but slower due to ripple propagation time and variance with Vcc and temperature. Thus static timing analysis must include worst case delays, setup, (...)
40MHz is the maximum clock rate the RAM can operate at reliably. If you try and operate it faster you will violate setup and hold time requirements. and just because your PROCESSOR is running at 104MHz doesn't mean your memory is running at that speed. With no knowledge (...)
regardless of any parameters What is "any parameter"? Sounds pretty meaningless. To answer the question for a given logic family, look at hold time and propagation time. You'll notice that it works for any usual logic family. No relation to setup (...)
worst case, means the lowest speed for the element, so if you reach your target frequency in this corner your design will reach at least the same frequency in the best corner (fastest speed). For the hold time, below 130nm, it is better to check the hold time in best and (...)
Hi, Please tell me how to calculate setup and hold time for TSPC based DFF Specifications are, time Period ( T ) = 500 ps Delay : < 250ps(*50% of T) I/P rise (...)
Short answer: setup and hold time
So before looking to the setup/hold time report, you must have the trans/cap violations clean or so small than the impact is reduce. So rca - Lets consider PT - so all you are saying is first of all check for Max trans/cap, fix it, and then you check setup/hold (...)
It will affect setup and hold of F2 only if you change the drive strength of F1 to the extent that it has much impact on rise and fall time at F2 data input. If the logic between F1 and F2 is deep enough and has cells with reasonably good drive strengths, (...)
Hi Esakki raja , Follow the below links. Thanks, Alam
Used STA tool to do eco fixing, and it will report the cell needed to fix the timing issue. But the first question, are you able to fix the hold after CTS or/and after routing?
hello every one, can any one explain about How to calculate library setup time and hold time? Thanks in Advance RGR
Hi Every one The library setup and hold times are generally in the library (.db or .lib) and how these are calculated? Here is the Example Report. data arrival time 0.57 clock mck (rise edge) 2.50 2.50 clock network delay (ideal) 0.00 2.50 (...)
I think you should forget about primetime and study the basics of the hold time. setup time = max of all data delays - min of all clk delays. hold time = max of clock delays - min of all (...)
How do i calculate the frequency of D flip flop in cadence? Also, i am stuck up with the setup and hold time calculation in cadence.
Hi , setup time: hold the clock steady.. and move the data delay well before the sensing edge ..., at some delay before the sensing edge.. the DFF will fail to reproduce the data...then the time difference between clock sensing edge and the data (...)
Will setup and hold time for D_latch and D_FF will be same if they are fabricated via same technology? In multi-clock design, In case of FF we wait for next rising/falling edge and check the setup time at that particular (...)
HI deepen, Basically lockup latches are used scan based design. 1.two different clock domains > Positive or negative level latch?? It depends on the path you are inserting a lockup latch. Since, lockup latches are inserted for hold timing; these are not needed where the path starts at a positive edge-triggered flop and ends at a negative edge
Hello sir. I am reading about lockup latches. Sir how exactly lockup cell removes the hold violation? and sir why we do check setup analysis in next clock and not at the same clock? If first clock for destination clock laging the source clock and during that time if data can (...)
setup time is a flip-flop specification that is typically provided to you by a manufacturer, and is relative to a single clock edge into a flop. However, setup-violation occurs when one driving flop feeds a signal into a second receiving flop, and the propagation of the signal between them (...)
many ways to fix setup violation after synthesis. 1. size cell and minimize data path delay. 2. check hold margin and useful skew. 3. use LVT cell if all ways can not work. you 'd better add more margin to re-synthesis or re-design.
Hi, This article might be useful
Hi plz anybody can help me as want to know the slew time for ddr2 signal is measured with which reference as from VINHAC to VINLDC for Falling and VINLAC to VINHDC FOR Rising or from the vref crossing point to VINHAC for rising and Vref to VINLAC for falling edge.
Just holding data 'long enough' is not good enough for asynchronous clock domains. You still have to meet setup and hold times in the receiving domain, and just because the data was stable for a long time(many receiver clock cycles) is no (...)
The setup/hold time calculation can be referred to report_delay_calculation during Design Compiler. Basically, the tool will refer to the timing table provided by .lib and calculate the result with input clock transition.
You can't have a clock with a period of 3ns and an offset of 3ns. What you are saying is that you want a setup/hold time equal to the clock period-->physically impossible. Maybe what you want is a multi-cycle constraint? What is it you are REALLY trying to specify here?
Hai all, What is Recovery Check,Removal Check? please could u tell me Eqs for Recovery check,Removal Check like setup time and hold time ? Thank u............
you can use data_check command in primetime to check signals which are not in the setup and hold format in the library. The data check commands are designed for the purposes of timing checks between handshaking systems.
Hi, 1. Negative hold time means that the hold value is very small and in real cases will be assumed to be zero. 2. The negative hold time should be good as if there are hold delay in final chip it will becoma a garbage. (...)
Adding capacitance to a net will increased the net delay, impact setup and hold time.
setup time is the time for which the data must be stable at the D input before the clock edge; hold time is the time for which data must be stable AFTER the clock edge.