Altera's DE2-115 User Manual
Altera's DE2-115 Pins Assignment
Quartus II Setting File with Pin Assignments for DE2-115
Cyclone IV Handbook (3 volumes)
Quartus II v. 13.1 online Help
Altera's Recommended HDL Coding Style
VHDL Language Guide (Accolade)
VHDL Designer's Guide (Dolous)
IEEE Standard VHDL Language Reference Manual: Std 1076-2000
IEEE Standard VHDL Language Reference Manual: Std 1076-2008
Accellera System Initiative
std_logic_1164 (ieee)
std_logic_arith (ieee)
std_logic_unsigned (ieee)
std_logic_signed (ieee)
numeric_std (ieee)
textio (std)
std_logic_textio (ieee)
standard (std)