Managing Macros - Managing Macros - 2026.1 English - UG903

Macros are stored as XDC constraints. Because they are Tcl commands, you can use them in both XDC constraint files and Tcl scripts, as well as interactively.

Write macros with the write_xdc command. Read macros with the read_xdc command. Use the -cell option to limit scope to specific cells. The -cell option is especially useful for applying a relative placement from one macro to similar instances in different hierarchies.

Managing Macros Example One

Write all XDC constraints in memory, including macros:

% write_xdc constrs.xdc

Managing Macros Example Two

A design contains three instances of a cell: inst_0, inst_1, and inst_2.

A macro is created inside inst_0:

% create_macro m0
% update_macro m0 {reg0 X0Y0 reg1 X0Y1}
% write_xdc -cell inst_0 inst_0.xdc

Managing Macros Example Three

Write all XDC constraints, including macro m0, for the cell inst_0:

% write_xdc -cell inst_0.xdc inst_0.xdc

Managing Macros Example Four

Read the XDC constraints, including macro m0 from cell inst_0, and apply them to inst_1 and inst_2:

% read_xdc inst_0.xdc -cell {inst_1 inst_2}
% get_macros
m0 inst_1_m0 inst_2_m0