Set external delay
Syntax
set_external_delay ‑from <args> ‑to <args> [‑min] [‑max] [‑add] [‑quiet]
[‑verbose] <delay_value>Usage
| Name | Description |
|---|---|
-from
|
Output port |
-to
|
Input port |
[-min]
|
Specifies minimum delay |
[-max]
|
Specifies maximum delay |
[-add]
|
Add to existing external delay |
[-quiet]
|
Ignore command errors |
[-verbose]
|
Suspend message limits during command execution |
<delay_value>
|
External (feedback) delay value |
Description
Sets the external (feedback) delay in nanoseconds (ns) between an output and input port. The external delay is used in the calculation of the PLL/MMCM compensation delay for PLLs/MMCMs with external feedback.
A min or max value can be specified. By default the value specified applies to both min (hold) and max (setup) compensation delays.
The command returns the defined delay.
Arguments
-from <arg> - (Required) The output port name.
-to <arg> - (Required) The input port name.
-min - (Optional) Specifies the delay_value is a minimum delay value for hold time analysis.
-max - (Optional) Specifies the delay_value is a maximum delay value for setup analysis.
-add - (Optional) Add the specified delay to the existing external delay value.
-quiet - (Optional) Execute the command quietly, returning no messages from the command. The command also returns TCL_OK regardless of any errors encountered during execution.
-verbose - (Optional) Temporarily override any message limits and return all messages from this command.
set_msg_config command.<delay_value> - (Required) The external delay value specified as nanoseconds (ns). The default value is 0.
Examples
The following example sets the external feedback delay to 1.0 ns between the port ClkOut and ClkFb:
set_external_delay -from [get_ports ClkOut] -to [get_ports ClkFb] 1.0