Range Specification
Formal Definition
The range specification can be used to specify an array of gate or
module instances.
Simplified Syntax
instance_name[l_index:r_index]
(list of terminals);
Description
The range should be specified using two constant expressions
separated by a colon and bracketed by square brackets. The
expressions constitutes: the left-hand index (l_index)
and right-hand index (r_index).
The left-hand index can be less than, equal, or greater than the
right-hand index (Example 1).
If these indexes are equal then only one instance will be generated (Example
2). Identical instance names cannot appear twice with other
range specifications (even if ranges do not overlap each other).
Examples
Example 1
reg [3:0] a, b;
wire [3:0] y;
and g[3:0](y,a,b);
This declaration is equivalent to:
and g3 (y[3], a[3], b[3]);
and g2 (y[2], a[2], b[2]);
and g1 (y[1], a[1], b[1]);
and g0 (y[0], a[0], b[0]);
Example 2
reg a, b;
wire y;
or g[0:0](y,a,b);
This declaration is equivalent to:
or g (y, a, b);
Important Notes
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