Sequencing CNT/DLY Blocks

Sequencing CNT/DLY Blocks

Timing Functions Technique

This technique will work with any GreenPAK.

DLY blocks can be chained together to sequence signals. By chaining the output of one delay block to the input of another a sequential set of delays can be made.

Figure 10 Sequential Rising Edge Delays

The DLY blocks in the sequential set should be set to Delay in the Mode setting within the Properties window. Typically, the Edge select setting should be the same for all sequenced components. Figure 11 shows the effect of the two sequential CNT/DLY blocks set to rising-edge, 8ms delays of the Power-On-Reset (POR) signal.

Figure 11 Sequential Delay Simulation

 

One can also chain together CNT blocks for a longer counted time.  When Chaining CNT blocks together, the CLK of the CNT should be driven by the output of the previous counter.  This can be done in the properties by selecting a CNT block and in the Properties window, choosing the Clock connection to be sourced from the previous CNTx/DLYx.

Figure 12 Sequential Counters

 

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