Along with science’s and technology’s development as well as living standards’ enhancement, in the modern life, the colored lantern takes one kind of decoration, both may strengthen people’s feeling view, plays the advertisements propaganda the role, and may increase the festive atmosphere, is sharp for people’s life addition, uses strengthens the party lighting effects in the stage. Along with electronic technology’s development, the application system turns toward the miniaturization, fast, large capacity, the weight light direction to develop, EDA (Elect ron icDesign A u tom at ic) the technical application causes the electronic products and the system development revolutionary transformation. The VHDL language takes programmable logical component’s standard language descriptive power, the coverage is broad, abstract ability, is getting more and more widespread in the practical application. In this stage, the people start to pursue the implementation overall system design the automation, may extricate thoroughly from the arduous project work, concentrates the energy in the creative plan and the concept idea, thus may raise the rated capacity, reduces product the development cycle. The entire process completes automatically through the EDA tool, reduced designers’ working strength greatly, improved the design quality, reduced the opportunity which makes a mistake.
VHDL is one kind of process standardization authentication hardware description language which the United States Department of Defense proposed, uses the VHDL language to carry on the hardware design to have the following characteristic: An engineering design (either said that exterior design entity) divides into (or calls visible part, namely port) and the interior (or said that invisible part), namely the design entity’s internal function and the algorithm complete the part.
This article introduced that applies American ALTERA Corporation’s MAX PLUSⅡThe platform, uses 16 group colored lantern control system which the VHDL hardware description language realizes.
16 group colored lantern control system’s realization
By 1 represents the lamp in the electric circuit to be bright, by 0 extinguishes on behalf of the lamp, by 0, 1 presses the different rule combination to represent the different light design, simultaneously causes its choice different frequency, thus realizes many kinds of design many kinds of frequency pattern function demonstrations. Only needs the simple updated program in this electric circuit to be possible to adjust the colored lantern design and the change way nimbly. Below carries on the simple declaration take a 16 group colored lantern control system’s realization as the example.
Functional description
This 16 group colored lantern control system hypothesis has four kind of pattern changes, these four kind of patterns may carry on the automatic cut over, and each kind of pattern may choose the different frequency, four kind of patterns respectively are:
(1) colored lantern from right to left, then produces the twinkle gradually from left to right.
(2) colored lantern lightens from right to left, then extinguishes in turn gradually from left to right, entire bright all extinguishes.
(3) colored lantern nearby two simultaneously shines 2 to disperse again gradually to the middle migration.
(4) colored lantern nearby two simultaneously shines 4, 4 bright 4 extinguish.
Principle of design
Carries on the design with VHDL, first should understand, the VHDL language is one kind of omni-directional hardware description language, including system behavior level, register transmission level and logical gate level many design levels. Should use VHDL fully “from the top” the design merit as well as the hierarchical design concept, the level concept regarding the design complex number system is very useful, it causes us to be possible to obtain from the simple unit, constitutes huge and the complex system gradually.
First should carry on the system module the division, stipulated each module the function as well as each module asked connection. The final design proposal is: By a 16 group colored lantern pattern controller, a four frequency output frequency divider, four choose a controller and time gate altogether four parts completes the design. Four choose a controller to transport from the frequency divider choice different frequency clock signal to the colored lantern pattern controller, thus achieves the control colored lantern twinkle speed the speed, the time gate controls each kind of speed maintenance the time length.
Entire 16 group colored lantern control system design’s module chart as shown in Figure 1.
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Submodule and function
This design divides into four sub-modules, namely 16 group colored lantern pattern controller, four frequency output frequency divider, four choose a controller and when asks the selector, its submodule and the function are as follows:
(1) four frequency output frequency divider: In this design, we have only designed four kind of patterns, we request these four kind of patterns to demonstrate by the different frequency, but only then an input clock signal, therefore we to input the clock signal carries on 2 frequency divisions, 4 frequency divisions, 8 frequency divisions, 16 frequency divisions, obtains four kind of frequency codes, the CLKDIV module is completes this function.
(2) time gate: The time gate in fact is two frequency dividers, a frequency is another frequency two times. These two frequency dividers may realize originally in the above four frequency follower, but to is conveniently four chooses a controller to provide the different time selection condition, independently comes these two frequency dividers. These two outputs the clock signal combines may be four chooses a controller to provide 00, 01, 10, 114 time selection condition, as shown in Figure 2.
(3) four choose a controller: Four choose a controller function is chooses the different frequency from the frequency divider the clock signal to give the colored lantern controller, realizes the colored lantern twinkle frequency shift.
(4) colored lantern controller: The colored lantern control circuit is the entire design core, it is responsible for the entire design the output effect namely each kind of colored lantern design style change. This procedure showed fully with the VHDL designa circuit “the ball” the nature, then the output variable Q figure changes colored lantern’s number through the alter procedure. And, the P1 advancement the speed which dodges to the lamp carries on the control, two ways may change the speed which the lamp dodges: First, changes external clock’s evaluation; second, changes signal U the figure. The P2 advancement can carry on colored lantern’s design control, changes s the figure then to change must control the design the number, the change output variable O combination then fluctuates the colored lantern design. The colored lantern controller realizes the procedure to be as follows:
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Librarv ieee;
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Its simulation profile as shown in Figure 3, module mark as shown in Figure 4.
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Simulation result
Finally, after when each module completes the above operation, then using the MAXPLLUS2 schematic diagram input, transfers each primary device (bottom document), forms the final 16 group colored lantern display system by the schematic diagram form (top document), and carries on the simulation. The simulation passes, then downloads to inside the CPLD chip which assigns, and carries on the actual segment, carries on the final hardware test. Certainly, may the part mark which produces each module deposit in the part storehouse, by is redundant the transfer by other human or other designs, simplifies the following design.
Compares with other hardware design method, carries on the engineering design with VHDL the merit is various: VHDL has the very strong behavior descriptive power, supports the large-scale design the decomposition and had the design again use, the readability is good, easy to revise and the discovery mistake, may use the simulator to carry on the simulation to the VHDL source code, allows the designer not to rely on the component, easy to discover in the design appears question, so that stitch in time. Can realize the design to have nothing to do with the craft, the probability is good, the going on the market time is quick, the cost is low, ASI (: Merits and so on transplant. May realize compound circuit’s control using FPGA, this article is only applies its simple control design to realize the process specifically.
