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Does clock rate affect propagation delay?
The time taken by a standard cell to process an input signal and produce a corresponding output signal is referred to as the propagation delay. Propagation delay decreases with scaling of the technology node and it directly affects the maximum clock frequency of the system.
Why maximum delay rather than average delay should be considered while designing the logic circuits?
The maximum delay constraint limits the number of consecutive gates on the critical path of a high-speed circuit, because a high clock frequency means a short clock period. Ben Bitdiddle designed the circuit in Figure 3.42. Help Ben determine the maximum clock frequency and whether any hold time violations could occur.
How is contamination delay calculated?
The sum of the propagation delay across these 2 gates is 2.1 + 1.5 = 3.6 ns. The contamination delay of a circuit is defined as the shortest delay from when the inputs change to when the outputs begin to change, or when the outputs are no longer guaranteed to be holding their previous stable value.
Is there a full clock period for combinational logic?
More than a full clock period becomes available for the combinational logic, unless the cumulated latch delay, clock skew and jitter eat up more time than T1 provides. In other words, the circuit can be made to operate in a wave pipelined regime as shown in fig.7.15. Figure 7.15. Anceau diagram of level-sensitive one-phase system.
What is the setup condition for combinational logic?
Combinational logic is fed with new data at the beginning of transparent interval T1 and must yield a stable result no later than at the end of the subsequent transparent interval. Once more, the setup condition is easily satisfied by acting on Tclk.
Which is the critical path in combinational logic?
The critical path, shown in blue, is the path from input A or B to output Y. It is the longest, and therefore the slowest, path, because the input travels through three gates to the output. This path is critical because it limits the speed at which the circuit operates.
Which is the minimum time for the propagation delay?
The propagation delay tpd is the maximum time from when an input changes until the output or outputs reach their final value. The contamination delay tcd is the minimum time from when an input changes until any output starts to change its value.