diff options
Diffstat (limited to 'libraries/ieee/numeric_bit.vhdl')
| -rw-r--r-- | libraries/ieee/numeric_bit.vhdl | 813 |
1 files changed, 813 insertions, 0 deletions
diff --git a/libraries/ieee/numeric_bit.vhdl b/libraries/ieee/numeric_bit.vhdl new file mode 100644 index 0000000..8f049f2 --- /dev/null +++ b/libraries/ieee/numeric_bit.vhdl @@ -0,0 +1,813 @@ +-- ----------------------------------------------------------------------------- +-- +-- Copyright 1995 by IEEE. All rights reserved. +-- +-- This source file is considered by the IEEE to be an essential part of the use +-- of the standard 1076.3 and as such may be distributed without change, except +-- as permitted by the standard. This source file may not be sold or distributed +-- for profit. This package may be modified to include additional data required +-- by tools, but must in no way change the external interfaces or simulation +-- behaviour of the description. It is permissible to add comments and/or +-- attributes to the package declarations, but not to change or delete any +-- original lines of the approved package declaration. The package body may be +-- changed only in accordance with the terms of clauses 7.1 and 7.2 of the +-- standard. +-- +-- Title : Standard VHDL Synthesis Package (1076.3, NUMERIC_BIT) +-- +-- Library : This package shall be compiled into a library symbolically +-- : named IEEE. +-- +-- Developers : IEEE DASC Synthesis Working Group, PAR 1076.3 +-- +-- Purpose : This package defines numeric types and arithmetic functions +-- : for use with synthesis tools. Two numeric types are defined: +-- : -- > UNSIGNED: represents an UNSIGNED number in vector form +-- : -- > SIGNED: represents a SIGNED number in vector form +-- : The base element type is type BIT. +-- : The leftmost bit is treated as the most significant bit. +-- : Signed vectors are represented in two's complement form. +-- : This package contains overloaded arithmetic operators on +-- : the SIGNED and UNSIGNED types. The package also contains +-- : useful type conversions functions, clock detection +-- : functions, and other utility functions. +-- : +-- : If any argument to a function is a null array, a null array is +-- : returned (exceptions, if any, are noted individually). +-- +-- Limitation : +-- +-- Note : No declarations or definitions shall be included in, +-- : or excluded from this package. The "package declaration" +-- : defines the types, subtypes and declarations of +-- : NUMERIC_BIT. The NUMERIC_BIT package body shall be +-- : considered the formal definition of the semantics of +-- : this package. Tool developers may choose to implement +-- : the package body in the most efficient manner available +-- : to them. +-- : +-- ----------------------------------------------------------------------------- +-- Version : 2.4 +-- Date : 12 April 1995 +-- ----------------------------------------------------------------------------- + +package NUMERIC_BIT is + constant CopyRightNotice: STRING + := "Copyright 1995 IEEE. All rights reserved."; + + --============================================================================ + -- Numeric array type definitions + --============================================================================ + + type UNSIGNED is array (NATURAL range <> ) of BIT; + type SIGNED is array (NATURAL range <> ) of BIT; + + --============================================================================ + -- Arithmetic Operators: + --============================================================================ + + -- Id: A.1 + function "abs" (ARG: SIGNED) return SIGNED; + -- Result subtype: SIGNED(ARG'LENGTH-1 downto 0). + -- Result: Returns the absolute value of a SIGNED vector ARG. + + -- Id: A.2 + function "-" (ARG: SIGNED) return SIGNED; + -- Result subtype: SIGNED(ARG'LENGTH-1 downto 0). + -- Result: Returns the value of the unary minus operation on a + -- SIGNED vector ARG. + + --============================================================================ + + -- Id: A.3 + function "+" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(MAX(L'LENGTH, R'LENGTH)-1 downto 0). + -- Result: Adds two UNSIGNED vectors that may be of different lengths. + + -- Id: A.4 + function "+" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(MAX(L'LENGTH, R'LENGTH)-1 downto 0). + -- Result: Adds two SIGNED vectors that may be of different lengths. + + -- Id: A.5 + function "+" (L: UNSIGNED; R: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0). + -- Result: Adds an UNSIGNED vector, L, with a non-negative INTEGER, R. + + -- Id: A.6 + function "+" (L: NATURAL; R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(R'LENGTH-1 downto 0). + -- Result: Adds a non-negative INTEGER, L, with an UNSIGNED vector, R. + + -- Id: A.7 + function "+" (L: INTEGER; R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(R'LENGTH-1 downto 0). + -- Result: Adds an INTEGER, L(may be positive or negative), to a SIGNED + -- vector, R. + + -- Id: A.8 + function "+" (L: SIGNED; R: INTEGER) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0). + -- Result: Adds a SIGNED vector, L, to an INTEGER, R. + + --============================================================================ + + -- Id: A.9 + function "-" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(MAX(L'LENGTH, R'LENGTH)-1 downto 0). + -- Result: Subtracts two UNSIGNED vectors that may be of different lengths. + + -- Id: A.10 + function "-" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(MAX(L'LENGTH, R'LENGTH)-1 downto 0). + -- Result: Subtracts a SIGNED vector, R, from another SIGNED vector, L, + -- that may possibly be of different lengths. + + -- Id: A.11 + function "-" (L: UNSIGNED; R: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0). + -- Result: Subtracts a non-negative INTEGER, R, from an UNSIGNED vector, L. + + -- Id: A.12 + function "-" (L: NATURAL; R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(R'LENGTH-1 downto 0). + -- Result: Subtracts an UNSIGNED vector, R, from a non-negative INTEGER, L. + + -- Id: A.13 + function "-" (L: SIGNED; R: INTEGER) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0). + -- Result: Subtracts an INTEGER, R, from a SIGNED vector, L. + + -- Id: A.14 + function "-" (L: INTEGER; R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(R'LENGTH-1 downto 0). + -- Result: Subtracts a SIGNED vector, R, from an INTEGER, L. + + --============================================================================ + + -- Id: A.15 + function "*" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED((L'LENGTH+R'LENGTH-1) downto 0). + -- Result: Performs the multiplication operation on two UNSIGNED vectors + -- that may possibly be of different lengths. + + -- Id: A.16 + function "*" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED((L'LENGTH+R'LENGTH-1) downto 0) + -- Result: Multiplies two SIGNED vectors that may possibly be of + -- different lengths. + + -- Id: A.17 + function "*" (L: UNSIGNED; R: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED((L'LENGTH+L'LENGTH-1) downto 0). + -- Result: Multiplies an UNSIGNED vector, L, with a non-negative + -- INTEGER, R. R is converted to an UNSIGNED vector of + -- size L'LENGTH before multiplication. + + -- Id: A.18 + function "*" (L: NATURAL; R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED((R'LENGTH+R'LENGTH-1) downto 0). + -- Result: Multiplies an UNSIGNED vector, R, with a non-negative + -- INTEGER, L. L is converted to an UNSIGNED vector of + -- size R'LENGTH before multiplication. + + -- Id: A.19 + function "*" (L: SIGNED; R: INTEGER) return SIGNED; + -- Result subtype: SIGNED((L'LENGTH+L'LENGTH-1) downto 0) + -- Result: Multiplies a SIGNED vector, L, with an INTEGER, R. R is + -- converted to a SIGNED vector of size L'LENGTH before + -- multiplication. + + -- Id: A.20 + function "*" (L: INTEGER; R: SIGNED) return SIGNED; + -- Result subtype: SIGNED((R'LENGTH+R'LENGTH-1) downto 0) + -- Result: Multiplies a SIGNED vector, R, with an INTEGER, L. L is + -- converted to a SIGNED vector of size R'LENGTH before + -- multiplication. + + --============================================================================ + -- + -- NOTE: If second argument is zero for "/" operator, a severity level + -- of ERROR is issued. + + -- Id: A.21 + function "/" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Divides an UNSIGNED vector, L, by another UNSIGNED vector, R. + + -- Id: A.22 + function "/" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Divides an SIGNED vector, L, by another SIGNED vector, R. + + -- Id: A.23 + function "/" (L: UNSIGNED; R: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Divides an UNSIGNED vector, L, by a non-negative INTEGER, R. + -- If NO_OF_BITS(R) > L'LENGTH, result is truncated to L'LENGTH. + + -- Id: A.24 + function "/" (L: NATURAL; R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(R'LENGTH-1 downto 0) + -- Result: Divides a non-negative INTEGER, L, by an UNSIGNED vector, R. + -- If NO_OF_BITS(L) > R'LENGTH, result is truncated to R'LENGTH. + + -- Id: A.25 + function "/" (L: SIGNED; R: INTEGER) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Divides a SIGNED vector, L, by an INTEGER, R. + -- If NO_OF_BITS(R) > L'LENGTH, result is truncated to L'LENGTH. + + -- Id: A.26 + function "/" (L: INTEGER; R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(R'LENGTH-1 downto 0) + -- Result: Divides an INTEGER, L, by a SIGNED vector, R. + -- If NO_OF_BITS(L) > R'LENGTH, result is truncated to R'LENGTH. + + --============================================================================ + -- + -- NOTE: If second argument is zero for "rem" operator, a severity level + -- of ERROR is issued. + + -- Id: A.27 + function "rem" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(R'LENGTH-1 downto 0) + -- Result: Computes "L rem R" where L and R are UNSIGNED vectors. + + -- Id: A.28 + function "rem" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(R'LENGTH-1 downto 0) + -- Result: Computes "L rem R" where L and R are SIGNED vectors. + + -- Id: A.29 + function "rem" (L: UNSIGNED; R: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Computes "L rem R" where L is an UNSIGNED vector and R is a + -- non-negative INTEGER. + -- If NO_OF_BITS(R) > L'LENGTH, result is truncated to L'LENGTH. + + -- Id: A.30 + function "rem" (L: NATURAL; R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(R'LENGTH-1 downto 0) + -- Result: Computes "L rem R" where R is an UNSIGNED vector and L is a + -- non-negative INTEGER. + -- If NO_OF_BITS(L) > R'LENGTH, result is truncated to R'LENGTH. + + -- Id: A.31 + function "rem" (L: SIGNED; R: INTEGER) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Computes "L rem R" where L is SIGNED vector and R is an INTEGER. + -- If NO_OF_BITS(R) > L'LENGTH, result is truncated to L'LENGTH. + + -- Id: A.32 + function "rem" (L: INTEGER; R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(R'LENGTH-1 downto 0) + -- Result: Computes "L rem R" where R is SIGNED vector and L is an INTEGER. + -- If NO_OF_BITS(L) > R'LENGTH, result is truncated to R'LENGTH. + + --============================================================================ + -- + -- NOTE: If second argument is zero for "mod" operator, a severity level + -- of ERROR is issued. + + -- Id: A.33 + function "mod" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(R'LENGTH-1 downto 0) + -- Result: Computes "L mod R" where L and R are UNSIGNED vectors. + + -- Id: A.34 + function "mod" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(R'LENGTH-1 downto 0) + -- Result: Computes "L mod R" where L and R are SIGNED vectors. + + -- Id: A.35 + function "mod" (L: UNSIGNED; R: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Computes "L mod R" where L is an UNSIGNED vector and R + -- is a non-negative INTEGER. + -- If NO_OF_BITS(R) > L'LENGTH, result is truncated to L'LENGTH. + + -- Id: A.36 + function "mod" (L: NATURAL; R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(R'LENGTH-1 downto 0) + -- Result: Computes "L mod R" where R is an UNSIGNED vector and L + -- is a non-negative INTEGER. + -- If NO_OF_BITS(L) > R'LENGTH, result is truncated to R'LENGTH. + + -- Id: A.37 + function "mod" (L: SIGNED; R: INTEGER) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Computes "L mod R" where L is a SIGNED vector and + -- R is an INTEGER. + -- If NO_OF_BITS(R) > L'LENGTH, result is truncated to L'LENGTH. + + -- Id: A.38 + function "mod" (L: INTEGER; R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(R'LENGTH-1 downto 0) + -- Result: Computes "L mod R" where L is an INTEGER and + -- R is a SIGNED vector. + -- If NO_OF_BITS(L) > R'LENGTH, result is truncated to R'LENGTH. + + --============================================================================ + -- Comparison Operators + --============================================================================ + + -- Id: C.1 + function ">" (L, R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L > R" where L and R are UNSIGNED vectors possibly + -- of different lengths. + + -- Id: C.2 + function ">" (L, R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L > R" where L and R are SIGNED vectors possibly + -- of different lengths. + + -- Id: C.3 + function ">" (L: NATURAL; R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L > R" where L is a non-negative INTEGER and + -- R is an UNSIGNED vector. + + -- Id: C.4 + function ">" (L: INTEGER; R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L > R" where L is a INTEGER and + -- R is a SIGNED vector. + + -- Id: C.5 + function ">" (L: UNSIGNED; R: NATURAL) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L > R" where L is an UNSIGNED vector and + -- R is a non-negative INTEGER. + + -- Id: C.6 + function ">" (L: SIGNED; R: INTEGER) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L > R" where L is a SIGNED vector and + -- R is a INTEGER. + + --============================================================================ + + -- Id: C.7 + function "<" (L, R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L < R" where L and R are UNSIGNED vectors possibly + -- of different lengths. + + -- Id: C.8 + function "<" (L, R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L < R" where L and R are SIGNED vectors possibly + -- of different lengths. + + -- Id: C.9 + function "<" (L: NATURAL; R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L < R" where L is a non-negative INTEGER and + -- R is an UNSIGNED vector. + + -- Id: C.10 + function "<" (L: INTEGER; R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L < R" where L is an INTEGER and + -- R is a SIGNED vector. + + -- Id: C.11 + function "<" (L: UNSIGNED; R: NATURAL) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L < R" where L is an UNSIGNED vector and + -- R is a non-negative INTEGER. + + -- Id: C.12 + function "<" (L: SIGNED; R: INTEGER) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L < R" where L is a SIGNED vector and + -- R is an INTEGER. + + --============================================================================ + + -- Id: C.13 + function "<=" (L, R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L <= R" where L and R are UNSIGNED vectors possibly + -- of different lengths. + + -- Id: C.14 + function "<=" (L, R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L <= R" where L and R are SIGNED vectors possibly + -- of different lengths. + + -- Id: C.15 + function "<=" (L: NATURAL; R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L <= R" where L is a non-negative INTEGER and + -- R is an UNSIGNED vector. + + -- Id: C.16 + function "<=" (L: INTEGER; R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L <= R" where L is an INTEGER and + -- R is a SIGNED vector. + + -- Id: C.17 + function "<=" (L: UNSIGNED; R: NATURAL) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L <= R" where L is an UNSIGNED vector and + -- R is a non-negative INTEGER. + + -- Id: C.18 + function "<=" (L: SIGNED; R: INTEGER) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L <= R" where L is a SIGNED vector and + -- R is an INTEGER. + + --============================================================================ + + -- Id: C.19 + function ">=" (L, R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L >= R" where L and R are UNSIGNED vectors possibly + -- of different lengths. + + -- Id: C.20 + function ">=" (L, R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L >= R" where L and R are SIGNED vectors possibly + -- of different lengths. + + -- Id: C.21 + function ">=" (L: NATURAL; R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L >= R" where L is a non-negative INTEGER and + -- R is an UNSIGNED vector. + + -- Id: C.22 + function ">=" (L: INTEGER; R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L >= R" where L is an INTEGER and + -- R is a SIGNED vector. + + -- Id: C.23 + function ">=" (L: UNSIGNED; R: NATURAL) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L >= R" where L is an UNSIGNED vector and + -- R is a non-negative INTEGER. + + -- Id: C.24 + function ">=" (L: SIGNED; R: INTEGER) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L >= R" where L is a SIGNED vector and + -- R is an INTEGER. + + --============================================================================ + + -- Id: C.25 + function "=" (L, R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L = R" where L and R are UNSIGNED vectors possibly + -- of different lengths. + + -- Id: C.26 + function "=" (L, R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L = R" where L and R are SIGNED vectors possibly + -- of different lengths. + + -- Id: C.27 + function "=" (L: NATURAL; R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L = R" where L is a non-negative INTEGER and + -- R is an UNSIGNED vector. + + -- Id: C.28 + function "=" (L: INTEGER; R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L = R" where L is an INTEGER and + -- R is a SIGNED vector. + + -- Id: C.29 + function "=" (L: UNSIGNED; R: NATURAL) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L = R" where L is an UNSIGNED vector and + -- R is a non-negative INTEGER. + + -- Id: C.30 + function "=" (L: SIGNED; R: INTEGER) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L = R" where L is a SIGNED vector and + -- R is an INTEGER. + + --============================================================================ + + -- Id: C.31 + function "/=" (L, R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L /= R" where L and R are UNSIGNED vectors possibly + -- of different lengths. + + -- Id: C.32 + function "/=" (L, R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L /= R" where L and R are SIGNED vectors possibly + -- of different lengths. + + -- Id: C.33 + function "/=" (L: NATURAL; R: UNSIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L /= R" where L is a non-negative INTEGER and + -- R is an UNSIGNED vector. + + -- Id: C.34 + function "/=" (L: INTEGER; R: SIGNED) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L /= R" where L is an INTEGER and + -- R is a SIGNED vector. + + -- Id: C.35 + function "/=" (L: UNSIGNED; R: NATURAL) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L /= R" where L is an UNSIGNED vector and + -- R is a non-negative INTEGER. + + -- Id: C.36 + function "/=" (L: SIGNED; R: INTEGER) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Computes "L /= R" where L is a SIGNED vector and + -- R is an INTEGER. + + --============================================================================ + -- Shift and Rotate Functions + --============================================================================ + + -- Id: S.1 + function SHIFT_LEFT (ARG: UNSIGNED; COUNT: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(ARG'LENGTH-1 downto 0) + -- Result: Performs a shift-left on an UNSIGNED vector COUNT times. + -- The vacated positions are filled with Bit '0'. + -- The COUNT leftmost bits are lost. + + -- Id: S.2 + function SHIFT_RIGHT (ARG: UNSIGNED; COUNT: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(ARG'LENGTH-1 downto 0) + -- Result: Performs a shift-right on an UNSIGNED vector COUNT times. + -- The vacated positions are filled with Bit '0'. + -- The COUNT rightmost bits are lost. + + -- Id: S.3 + function SHIFT_LEFT (ARG: SIGNED; COUNT: NATURAL) return SIGNED; + -- Result subtype: SIGNED(ARG'LENGTH-1 downto 0) + -- Result: Performs a shift-left on a SIGNED vector COUNT times. + -- The vacated positions are filled with Bit '0'. + -- The COUNT leftmost bits, except ARG'LEFT, are lost. + + -- Id: S.4 + function SHIFT_RIGHT (ARG: SIGNED; COUNT: NATURAL) return SIGNED; + -- Result subtype: SIGNED(ARG'LENGTH-1 downto 0) + -- Result: Performs a shift-right on a SIGNED vector COUNT times. + -- The vacated positions are filled with the leftmost bit, ARG'LEFT. + -- The COUNT rightmost bits are lost. + + --============================================================================ + + -- Id: S.5 + function ROTATE_LEFT (ARG: UNSIGNED; COUNT: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(ARG'LENGTH-1 downto 0) + -- Result: Performs a rotate-left of an UNSIGNED vector COUNT times. + + -- Id: S.6 + function ROTATE_RIGHT (ARG: UNSIGNED; COUNT: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(ARG'LENGTH-1 downto 0) + -- Result: Performs a rotate-right of an UNSIGNED vector COUNT times. + + -- Id: S.7 + function ROTATE_LEFT (ARG: SIGNED; COUNT: NATURAL) return SIGNED; + -- Result subtype: SIGNED(ARG'LENGTH-1 downto 0) + -- Result: Performs a logical rotate-left of a SIGNED vector COUNT times. + + -- Id: S.8 + function ROTATE_RIGHT (ARG: SIGNED; COUNT: NATURAL) return SIGNED; + -- Result subtype: SIGNED(ARG'LENGTH-1 downto 0) + -- Result: Performs a logical rotate-right of a SIGNED vector COUNT times. + + --============================================================================ + + ------------------------------------------------------------------------------ + -- Note : Function S.9 is not compatible with VHDL 1076-1987. Comment + -- out the function (declaration and body) for VHDL 1076-1987 compatibility. + ------------------------------------------------------------------------------ + -- Id: S.9 + function "sll" (ARG: UNSIGNED; COUNT: INTEGER) return UNSIGNED; --V93 + -- Result subtype: UNSIGNED(ARG'LENGTH-1 downto 0) + -- Result: SHIFT_LEFT(ARG, COUNT) + + ------------------------------------------------------------------------------ + -- Note : Function S.10 is not compatible with VHDL 1076-1987. Comment + -- out the function (declaration and body) for VHDL 1076-1987 compatibility. + ------------------------------------------------------------------------------ + -- Id: S.10 + function "sll" (ARG: SIGNED; COUNT: INTEGER) return SIGNED; --V93 + -- Result subtype: SIGNED(ARG'LENGTH-1 downto 0) + -- Result: SHIFT_LEFT(ARG, COUNT) + + ------------------------------------------------------------------------------ + -- Note : Function S.11 is not compatible with VHDL 1076-1987. Comment + -- out the function (declaration and body) for VHDL 1076-1987 compatibility. + ------------------------------------------------------------------------------ + -- Id: S.11 + function "srl" (ARG: UNSIGNED; COUNT: INTEGER) return UNSIGNED; --V93 + -- Result subtype: UNSIGNED(ARG'LENGTH-1 downto 0) + -- Result: SHIFT_RIGHT(ARG, COUNT) + + ------------------------------------------------------------------------------ + -- Note : Function S.12 is not compatible with VHDL 1076-1987. Comment + -- out the function (declaration and body) for VHDL 1076-1987 compatibility. + ------------------------------------------------------------------------------ + -- Id: S.12 + function "srl" (ARG: SIGNED; COUNT: INTEGER) return SIGNED; --V93 + -- Result subtype: SIGNED(ARG'LENGTH-1 downto 0) + -- Result: SIGNED(SHIFT_RIGHT(UNSIGNED(ARG), COUNT)) + + ------------------------------------------------------------------------------ + -- Note : Function S.13 is not compatible with VHDL 1076-1987. Comment + -- out the function (declaration and body) for VHDL 1076-1987 compatibility. + ------------------------------------------------------------------------------ + -- Id: S.13 + function "rol" (ARG: UNSIGNED; COUNT: INTEGER) return UNSIGNED; --V93 + -- Result subtype: UNSIGNED(ARG'LENGTH-1 downto 0) + -- Result: ROTATE_LEFT(ARG, COUNT) + + ------------------------------------------------------------------------------ + -- Note : Function S.14 is not compatible with VHDL 1076-1987. Comment + -- out the function (declaration and body) for VHDL 1076-1987 compatibility. + ------------------------------------------------------------------------------ + -- Id: S.14 + function "rol" (ARG: SIGNED; COUNT: INTEGER) return SIGNED; --V93 + -- Result subtype: SIGNED(ARG'LENGTH-1 downto 0) + -- Result: ROTATE_LEFT(ARG, COUNT) + + ------------------------------------------------------------------------------ + -- Note : Function S.15 is not compatible with VHDL 1076-1987. Comment + -- out the function (declaration and body) for VHDL 1076-1987 compatibility. + ------------------------------------------------------------------------------ + -- Id: S.15 + function "ror" (ARG: UNSIGNED; COUNT: INTEGER) return UNSIGNED; --V93 + -- Result subtype: UNSIGNED(ARG'LENGTH-1 downto 0) + -- Result: ROTATE_RIGHT(ARG, COUNT) + + ------------------------------------------------------------------------------ + -- Note : Function S.16 is not compatible with VHDL 1076-1987. Comment + -- out the function (declaration and body) for VHDL 1076-1987 compatibility. + ------------------------------------------------------------------------------ + -- Id: S.16 + function "ror" (ARG: SIGNED; COUNT: INTEGER) return SIGNED; --V93 + -- Result subtype: SIGNED(ARG'LENGTH-1 downto 0) + -- Result: ROTATE_RIGHT(ARG, COUNT) + + --============================================================================ + -- RESIZE Functions + --============================================================================ + + -- Id: R.1 + function RESIZE (ARG: SIGNED; NEW_SIZE: NATURAL) return SIGNED; + -- Result subtype: SIGNED(NEW_SIZE-1 downto 0) + -- Result: Resizes the SIGNED vector ARG to the specified size. + -- To create a larger vector, the new [leftmost] bit positions + -- are filled with the sign bit (ARG'LEFT). When truncating, + -- the sign bit is retained along with the rightmost part. + + -- Id: R.2 + function RESIZE (ARG: UNSIGNED; NEW_SIZE: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(NEW_SIZE-1 downto 0) + -- Result: Resizes the UNSIGNED vector ARG to the specified size. + -- To create a larger vector, the new [leftmost] bit positions + -- are filled with '0'. When truncating, the leftmost bits + -- are dropped. + + --============================================================================ + -- Conversion Functions + --============================================================================ + + -- Id: D.1 + function TO_INTEGER (ARG: UNSIGNED) return NATURAL; + -- Result subtype: NATURAL. Value cannot be negative since parameter is an + -- UNSIGNED vector. + -- Result: Converts the UNSIGNED vector to an INTEGER. + + -- Id: D.2 + function TO_INTEGER (ARG: SIGNED) return INTEGER; + -- Result subtype: INTEGER + -- Result: Converts a SIGNED vector to an INTEGER. + + -- Id: D.3 + function TO_UNSIGNED (ARG, SIZE: NATURAL) return UNSIGNED; + -- Result subtype: UNSIGNED(SIZE-1 downto 0) + -- Result: Converts a non-negative INTEGER to an UNSIGNED vector with + -- the specified size. + + -- Id: D.4 + function TO_SIGNED (ARG: INTEGER; SIZE: NATURAL) return SIGNED; + -- Result subtype: SIGNED(SIZE-1 downto 0) + -- Result: Converts an INTEGER to a SIGNED vector of the specified size. + + --============================================================================ + -- Logical Operators + --============================================================================ + + -- Id: L.1 + function "not" (L: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Termwise inversion + + -- Id: L.2 + function "and" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Vector AND operation + + -- Id: L.3 + function "or" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Vector OR operation + + -- Id: L.4 + function "nand" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Vector NAND operation + + -- Id: L.5 + function "nor" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Vector NOR operation + + -- Id: L.6 + function "xor" (L, R: UNSIGNED) return UNSIGNED; + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Vector XOR operation + + ------------------------------------------------------------------------------ + -- Note : Function L.7 is not compatible with VHDL 1076-1987. Comment + -- out the function (declaration and body) for VHDL 1076-1987 compatibility. + ------------------------------------------------------------------------------ + -- Id: L.7 + function "xnor" (L, R: UNSIGNED) return UNSIGNED; --V93 + -- Result subtype: UNSIGNED(L'LENGTH-1 downto 0) + -- Result: Vector XNOR operation + + -- Id: L.8 + function "not" (L: SIGNED) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Termwise inversion + + -- Id: L.9 + function "and" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Vector AND operation + + -- Id: L.10 + function "or" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Vector OR operation + + -- Id: L.11 + function "nand" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Vector NAND operation + + -- Id: L.12 + function "nor" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Vector NOR operation + + -- Id: L.13 + function "xor" (L, R: SIGNED) return SIGNED; + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Vector XOR operation + + ------------------------------------------------------------------------------ + -- Note : Function L.14 is not compatible with VHDL 1076-1987. Comment + -- out the function (declaration and body) for VHDL 1076-1987 compatibility. + ------------------------------------------------------------------------------ + -- Id: L.14 + function "xnor" (L, R: SIGNED) return SIGNED; --V93 + -- Result subtype: SIGNED(L'LENGTH-1 downto 0) + -- Result: Vector XNOR operation + + --============================================================================ + -- Edge Detection Functions + --============================================================================ + + -- Id: E.1 + function RISING_EDGE (signal S: BIT) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Returns TRUE if an event is detected on signal S and the + -- value changed from a '0' to a '1'. + + -- Id: E.2 + function FALLING_EDGE (signal S: BIT) return BOOLEAN; + -- Result subtype: BOOLEAN + -- Result: Returns TRUE if an event is detected on signal S and the + -- value changed from a '1' to a '0'. + +end NUMERIC_BIT; |