top.bdf

这是用VHDL编写的译码程序,程序简单易懂

/*
WARNING: Do NOT edit the input and output ports in this file in a text
editor if you plan to continue editing the block that represents it in
the Block Editor! File corruption is VERY likely to occur.
*/
/*
Copyright (C) 1991-2005 Altera Corporation
Your use of Altera Corporation's design tools, logic functions 
and other software and tools, and its AMPP partner logic       
functions, and any output files any of the foregoing           
(including device programming or simulation files), and any    
associated documentation or information are expressly subject  
to the terms and conditions of the Altera Program License      
Subscription Agreement, Altera MegaCore Function License       
Agreement, or other applicable license agreement, including,   
without limitation, that your use is for the sole purpose of   
programming logic devices manufactured by Altera and sold by   
Altera or its authorized distributors.  Please refer to the    
applicable agreement for further details.
*/
(header "graphic" (version "1.3"))
(pin
	(input)
	(rect 64 120 232 136)
	(text "INPUT" (rect 133 0 161 10)(font "Arial" (font_size 6)))
	(text "sel[2..0]" (rect 5 0 45 12)(font "Arial" ))
	(pt 168 8)
	(drawing
		(line (pt 92 12)(pt 117 12)(line_width 1))
		(line (pt 92 4)(pt 117 4)(line_width 1))
		(line (pt 121 8)(pt 168 8)(line_width 1))
		(line (pt 92 12)(pt 92 4)(line_width 1))
		(line (pt 117 4)(pt 121 8)(line_width 1))
		(line (pt 117 12)(pt 121 8)(line_width 1))
	)
	(text "VCC" (rect 136 7 156 17)(font "Arial" (font_size 6)))
	(annotation_block (location)(rect -40 64 40 120))
)
(pin
	(input)
	(rect 64 136 232 152)
	(text "INPUT" (rect 133 0 161 10)(font "Arial" (font_size 6)))
	(text "clk" (rect 5 0 19 12)(font "Arial" ))
	(pt 168 8)
	(drawing
		(line (pt 92 12)(pt 117 12)(line_width 1))
		(line (pt 92 4)(pt 117 4)(line_width 1))
		(line (pt 121 8)(pt 168 8)(line_width 1))
		(line (pt 92 12)(pt 92 4)(line_width 1))
		(line (pt 117 4)(pt 121 8)(line_width 1))
		(line (pt 117 12)(pt 121 8)(line_width 1))
	)
	(text "VCC" (rect 136 7 156 17)(font "Arial" (font_size 6)))
	(annotation_block (location)(rect -40 152 48 184))
)
(pin
	(input)
	(rect 64 152 232 168)
	(text "INPUT" (rect 133 0 161 10)(font "Arial" (font_size 6)))
	(text "en" (rect 5 0 16 12)(font "Arial" ))
	(pt 168 8)
	(drawing
		(line (pt 92 12)(pt 117 12)(line_width 1))
		(line (pt 92 4)(pt 117 4)(line_width 1))
		(line (pt 121 8)(pt 168 8)(line_width 1))
		(line (pt 92 12)(pt 92 4)(line_width 1))
		(line (pt 117 4)(pt 121 8)(line_width 1))
		(line (pt 117 12)(pt 121 8)(line_width 1))
	)
	(text "VCC" (rect 136 7 156 17)(font "Arial" (font_size 6)))
	(annotation_block (location)(rect -24 224 64 256))
)
(pin
	(output)
	(rect 360 120 536 136)
	(text "OUTPUT" (rect 1 0 39 10)(font "Arial" (font_size 6)))
	(text "Y[7..0]" (rect 90 0 124 12)(font "Arial" ))
	(pt 0 8)
	(drawing
		(line (pt 0 8)(pt 52 8)(line_width 1))
		(line (pt 52 4)(pt 78 4)(line_width 1))
		(line (pt 52 12)(pt 78 12)(line_width 1))
		(line (pt 52 12)(pt 52 4)(line_width 1))
		(line (pt 78 4)(pt 82 8)(line_width 1))
		(line (pt 82 8)(pt 78 12)(line_width 1))
		(line (pt 78 12)(pt 82 8)(line_width 1))
	)
	(annotation_block (location)(rect 472 144 592 272))
)
(symbol
	(rect 232 96 360 192)
	(text "decoder" (rect 5 0 43 12)(font "Arial" ))
	(text "inst" (rect 8 80 25 92)(font "Arial" ))
	(port
		(pt 0 32)
		(input)
		(text "sel[2..0]" (rect 0 0 40 12)(font "Arial" ))
		(text "sel[2..0]" (rect 21 27 61 39)(font "Arial" ))
		(line (pt 0 32)(pt 16 32)(line_width 3))
	)
	(port
		(pt 0 48)
		(input)
		(text "clk" (rect 0 0 14 12)(font "Arial" ))
		(text "clk" (rect 21 43 35 55)(font "Arial" ))
		(line (pt 0 48)(pt 16 48)(line_width 1))
	)
	(port
		(pt 0 64)
		(input)
		(text "en" (rect 0 0 11 12)(font "Arial" ))
		(text "en" (rect 21 59 32 71)(font "Arial" ))
		(line (pt 0 64)(pt 16 64)(line_width 1))
	)
	(port
		(pt 128 32)
		(output)
		(text "Y[7..0]" (rect 0 0 34 12)(font "Arial" ))
		(text "Y[7..0]" (rect 73 27 107 39)(font "Arial" ))
		(line (pt 128 32)(pt 112 32)(line_width 3))
	)
	(drawing
		(rectangle (rect 16 16 112 80)(line_width 1))
	)
)