VHDL Fő témakörök: VHDL-en alapuló áramkörtervezés VHDL alapok Fejlett VHDL nyelvi szerkezetek Áramköri példák

Gajski Y-diagrammja Az egyes tengelyek leírási típusokat képviselnek Viselkedési Fizikai Szerkezeti Processzorok, memóriák Regiszterek, multiplexerek Kapuk, flip-flopok Tranzisztorok Sorrendi programok Regiszter átvitelek Logikai egyenletek/FSM Átviteli függvények Cella layout Modulok Chipek Kártyák Az egyes tengelyek leírási típusokat képviselnek Viselkedési A bemenetek függvényében meghatározza a kimeneteket Algoritmus, de nem megvalósítás Szerkezeti Megvalósítja a viselkedést az ismert viselkedésű összetevők összekötésével Fizikai Megadja a chipbeli összetevők és vezetékekméretété és elhelyezését A tervezési folyamatot utazási útvonallal lehet ábrázolni

A VHDL története VHDL originated in the early 1980s It is now accepted as one of the most important standard languages for specifying verifying designing of electronics

VHDL szimulációhoz & szintézishez Tesztvektor generátor Finomított modellek sorozata Végrehajtható előírás Teszt-vektorok Eredmények, hibák = Végső chipModell

VHDL szimulációhoz & szintézishez VHDL requirements for Simulation Creation of testbenches => File I/O Detection of errors (function & timing) Multiple simultaneous models Combination of low & high level models (for efficiency)

VHDL szimulációhoz & szintézishez VHDL requirements for HW Description Behavioral models => Combinatorial & Sequential Logic RTL models Structural models Timing models

VHDL szimulációhoz & szintézishez Requirements for VHDL Synthesis Tools Pre- & post synthesis behavior should be identical Synthesis should be efficient => Requires interaction with place & route tools Logic Synthesis FSM Synthesis Area & Timing Optimization

Szabványosítás 1 VHDL is an acronym of VHSIC Hardware Description Language VHSIC is an acronym of Very High Speed Integrated Circuits All the major tool manufacturers now support the VHDL standard VHDL is now a standardized language, with the advantage that it it easy to move VHDL code between different commercial platforms (tools) => VHDL code is interchangeable among the different tools

Szabványosítás 2 It was the American Department of Defense which initiated the development of VHDL in the early 1980s because the US military needed a standardized method of describing electronic systems VHDL was standardized in 1987 by the IEEE IEEE Std-1076-1987 ANSI Standard in 1988 Added Support for RTL Design VITAL: VHDL Initiative Towards ASIC Library Revised version in 1993 IEEE Std-1076-1993

Szabványosítás 3 1995: 1999: IEEE-1076.1 (VHDL-AMS ) 2000: numeric_std/bit: IEEE-1076.3 VITAL: IEEE-1076.4 1999: IEEE-1076.1 (VHDL-AMS ) 2000: IEEE-1076-2000 IEEE-1076.1-2000 (VITAL-2000, SDF 4.0) Added mixed-signal support to VHDL in 2001 -> VHDL-AMS IEEE Std-1076.1-2001 2002: IEEE-1076-2002

Tervezőeszközök Good VHDL tools, and VHDL simulators in particular, have also been developed for PCs Prices have fallen dramatically, enabling smaller companies to use VHDL, too There are also PC synthesis tools, primarily for FPGAs and EPLDs

Használat High-tech companies Universities Texas Instruments, Intel use VHDL most European companies use VHDL Universities VHDL groups to support new users

IEEE IEEE is the Institute of Electrical and Electronics Engineers The reference manual is called IEEE VHDL Language Reference Manual Draft Standard version 1076/B It was ratified in December 1987 as IEEE 1076-1987 Important: the VHDL is standardized for system specification but not for design

Technológia-függetlenség The design of VHDL components can be technology-independent or more-or-less technology independent for a technical family The components can be stored in a library for reuse in several different designs VHDL models of commercial IC standard components can now be bought, which is a great advantage when it comes to verifying entire circuit boards

Analóg világ VHDL has not yet been standardized for analog electronics Standardization is in progress on VHDL with an analog extension (AHDL) to allow analog systems to be described as well This new standard will be based wholly on the VHDL standard and will have a number of additions for describing analog functions

VHDL-Related Newsgroups comp.arch.fpga comp.lang.vhdl comp.cad.synthesis