set_max_time_borrow - 2024.1 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

Document ID
UG835
Release Date
2024-05-30
Version
2024.1 English

Limit time borrowing for latches

Syntax

set_max_time_borrow [‑quiet] [‑verbose] <delay> <objects>

Usage

Name Description
[-quiet] Ignore command errors
[-verbose] Suspend message limits during command execution
<delay> Delay value: Value >= 0
<objects> List of clocks, cells, data pins or clock pins

Categories

SDC, XDC

Description

Sets the maximum amount of time in nanoseconds that can be borrowed between nets when analyzing the timing on latches.

Note: This command operates silently and does not return direct feedback of its operation.

Arguments

-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.
Note: Any errors encountered on the command-line, while launching the command, will be returned. Only errors occurring inside the command will be trapped.
-verbose - (Optional) Temporarily override any message limits and return all messages from this command.
Note: Message limits can be defined with the set_msg_config command.

<delay> - (Required) The delay that should be applied to the specified objects. The <delay> is specified in nanoseconds (ns) as a floating point number >= 0, with a default value of 0.

<objects> - (Required) A list of clocks, cells, data pins, or clock pins to which the limit should be applied.

Examples

The following example specifies that the latches attached to "all clocks" will be allowed 0 time units of borrowing. Effectively, this disables time borrowing throughout the entire design.

set_max_time_borrow 0.0 [all_clocks]

The following example specifies that nets in the top level of hierarchy are allowed 20 time units of time borrowing:

set_max_time_borrow 20 {top/*}