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Unformatted text preview: ht 2000, IEEE. All rights reserved. This is an unapproved IEEE Standards Draft, subject to change. 71 IEEE Std P1076a-1999 2000/D3 IEEE STANDARD VHDL e) Finally, if the name denotes a type, then implicit alias declarations for each predefined operator for the type immediately follow the explicit alias declaration for the type and, if present, any implicit alias declarations for literals or units of the type. Each implicit alias has a signature that matches the parameter and result type profile of the implicit operator being aliased. Examples: variable REAL_NUMBER : BIT_VECTOR (0 to 31); alias SIGN : BIT is REAL_NUMBER (0); -- SIGN is now a scalar (BIT) value alias MANTISSA : BIT_VECTOR (23 downto 0) is REAL_NUMBER (8 to 31); -- MANTISSA is a 24b value whose range is 23 downto 0. -- Note that the ranges of MANTISSA and REAL_NUMBER (8 to 31) -- have opposite directions. A reference to MANTISSA (23 downto 18) -- is equivalent to a reference to REAL_NUMBER (8 to 13). alias EXPONENT : BIT_VECTOR (1 to 7) is REAL_NUMBER (1 to 7); -- EXPONENT is a...
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This note was uploaded on 09/09/2009 for the course EECS 318 taught by Professor Saab during the Fall '01 term at Case Western.
- Fall '01