在进入下一个寄存器之前无法判决出稳定状态,造成亚稳态传播 同步寄存器(Synchronizer)和“打两拍”(Two flip-flop synchronizer) 打两拍并不能完全消除亚稳态。 打两拍并不意味着能正确采样。 MTBF(Mean Time Between Failure)平均失效间隔时间 C1和 C2是常数,依赖于器件工艺和操作环境。 fCLK和 fDATA参数取决于...
The most common way to tolerate metastability is to add one or more successive synchronizing flip-flops to the synchronizer. This approach allows for an entire clock period (except for the setup time of the second flip-flop) for metastable events in the first synchronizing flip-flop to resolve ...
Metastability of CMOS latch/flip-flop - Kim, Dutton - 1990 () Citation Context ...y utilizing bistable inverters, as shown in Figure 5.10, it has been suggested that the optimum device width ratio is 1:1(PMOS:NMOS) for maximizing the gain-bandwidth product of the synchronizer [23] =-=...
Neither of these approaches can guarantee that metastability cannot pass through the synchronizer; they simply reduce the probability to practical levels. In quantitative terms, if the Mean Time Between Failure (MTBF) of a particular flip-flop in the context of a given clock rate and input trans...
Now when I compile my project and run Time Quest, it recognizes the two flip flops within the "EdgeDetectNoEn" block as a Synchronizer chain within the "Report Metastability" report. I was able to force the two flip flops so Time Quest gave me the MTBF, but I am getting a timing viol...
To give a little background on my project, I wanted to use only a single flip-flop synchronizer to synchronize an asynchronous input signal. Although a double-stage synchronizer would be preferable, power consumption as well as latency are both critical in my system. Doubl...
A synchronizer eliminates metastability due to violation of either the setup time or the hold time of a circuit. The input of a first flip-flop () is tied to a constant logic level (VDD or ground). The first flip-flop receives an asynchronous signal into the reset (preset or clear) inp...
First, if you are implementing a synchronizer in a PLD, put the synchronizer flip-flop and destination flip-flops in the same part to minimize the delay from the synchronizer's output to its destination. Second, you can reduce the effects of metastability by using a multiple-stage synchronizer...
In electronic circuits, metastability refers to the persistence of a non-equilibrium electronic state for an extended period of time (i.e., for longer than a clock cycle). For example, a flip-flop is an electronic device that may suffer from metastability. It has two well-defined stable sta...
Comments on "Metastability of CMOS Latch/Flip-Flop' ' At this point, in this particular embodiment, control circuit 310 results in the impedance of buffer 330 varying by plus or minus a least significant control bit about the desired impedance value. The time to allow for metastability ... ...