The ALUS library consists of the following 4 generic components :

addN	:	N-bit adder
subN	:	N-bit subtractor
adsbN	:	N-bit adder / subtractor
aluNf	:	N-bit general purpose ALU with flags

The ALUS library can be verified with this testbench : test_alus

These particular components implements all the logical and arithmetic operations,
such as addition and substraction, with a variable word length of the operands.
In the next two tables, the general's ALU operations encoding is shown.

Arithmetic operations :

Operation	Expression	Mnemonic	Op Code
Add	A + B + CIN	ADD	1001111
Subtract	A + B~ + CIN	SUB	1000111
Reverse Subtract	B - A - CIN~	SBR	1001101
Negate A	A~ + CIN	NEGA	1000001
Negate B	B~ + CIN	NEGB	1000100
Increment A	A + CIN	INCA	1000011
Increment B	B + CIN	INCB	1001100
Decrement A	A - CIN~	DECA	1001011
Decrement B	B - CIN~	DECB	1001110
Negated Add	A~ + B~ + CIN	NADD	1000101
Decrement Not A	A~ + CIN~	NDECA	1001001
Decrement Not B	B~ + CIN~	NDECB	1000110

Logical Operations :

Operation	Expression	Mnemonic	Op Code
Ones	-1	ONES	0100000
Zeros	0	ZEROS	0100010
Pass A	A	EQUA	0100011
Pass B	B	EQUB	0101100
Not A	A~	NOTA	0100001
Not B	B~	NOTB	0100100
And	A * B	AND	1010101
And Complement A	A~ * B	ANDCA	1010111
And Complement B	A * B~	ANDCB	1011110
Nand	(A * B)~	NAND	0010101
Or	A + B	OR	0011111
Or Complement A	A~ + B	ORCA	0011101
Or Complement b	A + B~	ORCB	0010111
Nor	(A + B)~	NOR	1011111
Exclusive Or	A ^ B	XOR	0101111
Exclusive Nor	(A ^ B)~	XNOR	1101111