Digital Systems Modeling Chapter 2 VHDL-Based Design Alain Vachoux Microelectronic Systems Laboratory
[email protected] Digital Systems Modeling Chapter 2: VHDL-Based Design Chapter 2: Table of contents ♦ VHDL overview ♦ Synthesis with VHDL ♦ Test bench models & verification techniques A. Vachoux, 2004-2005 Digital Systems Modeling Chapter 2: VHDL-Based Design - 2 A. Vachoux 2004-2005 2-2 Digital Systems Modeling Chapter 2: VHDL-Based Design VHDL highlights (1/2) ♦ Hardware description language • Digital hardware systems • Modeling, simulation, synthesis, documentation • IEEE standard 1076 (1987, 1993, 2002) ♦ Originally created for simulation • IEEE standards 1164 (STD_LOGIC) and 1076.4 (VITAL) ♦ Further adapted to synthesis • Language subset • IEEE standards 1076.3 (packages) and 1076.6 (RTL semantics) A. Vachoux, 2004-2005 Digital Systems Modeling Chapter 2: VHDL-Based Design - 3 A. Vachoux 2004-2005 2-3 Digital Systems Modeling Chapter 2: VHDL-Based Design VHDL highlights (2/2) ♦ Application domain (abstraction levels): Functional -> logic ♦ Modularity • 5 design entities: entity, architecture, package declaration and body, configuration • Separation of interface from implementation • Separate compilation ♦ Strong typing • Every object has a type • Type compatibility checked at compile time ♦ Extensibility: User-defined types ♦ Model of time • Discrete time, integer multiple of some MRT (Minimum Resolvable Time) ♦ Event-driven simulation semantics A. Vachoux, 2004-2005 Digital Systems Modeling Chapter 2: VHDL-Based Design - 4 A. Vachoux 2004-2005 2-4 Digital Systems Modeling Chapter 2: VHDL-Based Design VHDL-based design flow Editor (text or graphic) Test bench models VHDL packages RTL model Logic simulation Logic/RTL Constraints synthesis (area, timing, power) VHDL VITAL standard cell Gate-level modeld netlist Standard cell library SDF file Place & route Delay Layout extraction A.