* Question
What Are the Main Parameters in the Clock to Clock Tab?
* Answer
The Clock to Clock tab contains three primary parameter fields: From Clock Edge, To Clock Edge, and Delay (ns). Together, these fields define a timing relationship between two clock edges.
From Clock Edge
From Clock Edge specifies the source or launch edge from which the timing measurement begins. Depending on the available settings, this may be the rising or falling edge of the source clock.
This field identifies the reference event that starts the clock-to-clock timing interval.
To Clock Edge
To Clock Edge specifies the destination or capture edge at which the timing measurement ends. It may refer to the rising or falling edge of the destination clock.
Combining the two edge fields allows the tool to define relationships such as:
- Rising edge to rising edge
- Rising edge to falling edge
- Falling edge to rising edge
- Falling edge to falling edge
Delay (ns)
Delay (ns) defines the time difference between the selected source and destination clock edges. The value is expressed in nanoseconds.
Depending on the tool, this parameter may represent an intentional clock offset, propagation delay, phase relationship, or timing constraint applied between the two edges.
For example, if From Clock Edge is set to a rising edge, To Clock Edge is set to the next rising edge, and Delay is set to 5 ns, the destination edge is defined as occurring 5 ns after the source edge.
These three parameters allow designers to describe and analyze clock relationships accurately. Before entering a value, verify how the specific software interprets positive and negative delays, edge numbering, and repeated clock cycles.
