28-12-2012, 04:40 PM
VHDL OPERATORS
1VHDL.pdf (Size: 169.99 KB / Downloads: 226)
There are seven groups of predefined VHDL operators:
1. Binary logical operators: and or nand nor xor xnor
2. Relational operators: = /= < <= > >=
3. Shifts operators: sll srl sla sra rol ror
4. Adding operators: + - &(concatenation)
5. Unary sign operators: + -
6. Multiplying operators: * / mod rem
7. Miscellaneous operators: not abs *
Two’s Complement Direct Integer Addition
This example uses an abstract integer ports. The integer addition can be done directly without integer-to-bit or bit-to-integer conversion. When using abstract port types, integer and user-defined enumerated ports are converted by Autologic VHDL to bit_vectors of the appropriate size. Only standard library is needed for this coding.