5 Signal Names and Types

Boolean

(simple) signals take values of #t and #f. Boolean identifiers start with an alphabetic character and followed by characters which are alphabetic, numeric, or

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Vectorized

signals represent multiple bits and assume integer values.

Vectorized signal names are written as boolean names followed with two integers separated by ‘..’ or ‘:’ and encased by square brackets (‘[31..0]’). The two integers specify an inclusive range. For example, foocnt[0..3] specifies a four-bit signal. The indexes can be in either order, but little-endian values must not be assigned to big-endian signals and vice versa.

The even/odd bit of vectorized values is always the lowest bit of the index pair. The designer is responsible for shifting vectorized signals to align as desired.

Aggregate

signals group multiple vectorized signals into arrays.