EDA课程设计 - 图文(4)

2、依次点击“MAX+plusⅡ→Programmer”后再点击菜单栏中的JTAG→Multi-Device JTAG Chain Setup”出现如下对话框(图8.3)，点击Select Programming File...,出现图8.4对话框，将1k30\\ Dac0832\\enddac0832.sof项目选中后点击OK，回到图8.3的对话框，点击ADD把此项目添加到“Multi-Device JTAG Chain Setup”对话框中，点击OK回到Programmer对话框。

按实验连线要求，把实验板上需要连接的导线或短路帽插好，最后打开电源，点击”Configure”即进行下载。下载成功后会出现成功的提示，反之会给出失败的提示。

图8.3

图8.4

3、打开顶层文件enddac0832.gdf如下：

现将原程序如下说明： ---打开dac0832.vhd

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library ieee;

use ieee.std_logic_1164.all; entity dac0832 is port(clk: in std_logic; ----D/A 转换控制时钟

dd: out integer range 255 downto 0; -- 待转换数据 dispdata: out integer range 255 downto 0);-- 待转换数据输出显示 end dac0832;

architecture behv of dac0832 is

signal q: integer range 63 downto 0; signal d: integer range 255 downto 0; begin

process(clk) begin

if (clk'event and clk ='1' ) then

q<=q+1; ---建立转换计数器 end if;

end process; process(q) begin

case q is ---64点正弦波波形数据输 when 00=> d<=255; when 01=> d<=254; when 02=> d<=252; when 03=> d<=249; when 04=> d<=245; when 05=> d<=239; when 06=> d<=233; when 07=> d<=225; when 08=> d<=217; when 09=> d<=207; when 10=> d<=197; when 11=> d<=186; when 12=> d<=174; when 13=> d<=162; when 14=> d<=150; when 15=> d<=137; when 16=> d<=124; when 17=> d<=112; when 18=> d<=99; when 19=> d<=87; when 20=> d<=75; when 21=> d<=64; when 22=> d<=53; when 23=> d<=43; when 24=> d<=34; when 25=> d<=26; when 26=> d<=19; when 27=> d<=13; when 28=> d<=8; when 29=> d<=4; when 30=> d<=1; when 31=> d<=0; when 32=> d<=0; when 33=> d<=1; when 34=> d<=4; when 35=> d<=8; when 36=> d<=13; when 37=> d<=19; when 38=> d<=26; when 39=> d<=34; when 40=> d<=43; when 41=> d<=53; when 42=> d<=64; when 43=> d<=75; when 44=> d<=87; when 45=> d<=99; when 46=> d<=112; when 47=> d<=124; when 48=> d<=137; when 49=> d<=150; when 50=> d<=162; when 51=> d<=174; when 52=> d<=186; when 53=> d<=197; when 54=> d<=207; when 55=> d<=217; when 56=> d<=225; when 57=> d<=233; when 58=> d<=239; when 59=> d<=245; when 60=> d<=249; when 61=> d<=252; when 62=> d<=254; when 63=> d<=255; when others=>NUll; end case;

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end process;

dd<=d; ----D/A转换数据输出 dispdata<=d; ----D/A转换数据显示 end behv;

引脚分配（ACEX EP1K30TC144-3）：

dout0-P5、dout1-P6、dout2-P7、dout3-P8、dout4-P9、dout5-P10、dout6-P11、 sel0-P78、sel1-P79、sel2-P80、writeout-P72 csdaout P60、db0-P48、db1-P49、db2-P50、db3-P51、db4-P52、db5-P53、db6-P54、db7-P58、csda-P35、write-P30

管脚标号write、csda分别接开关sw1、sw2；csdaout、writeout分别接DAC0832的CS,WR1；dd0到dd7接DAC0832的8位数字量输入线；dout0到dout6分别接LED的8位段码中的7位；sel0到sel2接到实验箱中74ls138的输入端；sysclk为LED显示的时钟输入,接到频率源clk3；daclk为数据发生模块的系统时钟,接到频率源clk2。

User

Assignments Node Name enddac0832@33 csda enddac0832@88 csdaout enddac0832@56 daclk enddac0832@44 dd0 enddac0832@46 dd1 enddac0832@47 dd2 enddac0832@48 dd3 enddac0832@49 dd4 enddac0832@51 dd5 enddac0832@59 dd6 enddac0832@60 dd7 enddac0832@144 dout0 enddac0832@8 dout1 enddac0832@9 dout2 enddac0832@10 dout3 enddac0832@12 dout4 enddac0832@13 dout5 enddac0832@17 dout6 enddac0832@101 sel0 enddac0832@102 sel1 enddac0832@117 sel2 enddac0832@119 sysclk enddac0832@32 write enddac0832@99 writeout 五、现象：

1、数码右端两个显示88，其余显示零。 2、示波器上显示正弦波信号。

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附 录 一

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