📄 http:^^www.cs.washington.edu^education^courses^467^fall96^lab^lab34^lab4.html
字号:
Date: Wed, 08 Jan 1997 21:42:38 GMTServer: NCSA/1.4.2Content-type: text/html<html><head><title>CSE467 Laboratory Assignment #4</title></head><body bgcolor="#dddddd" text="#000000" link="#0000ee" vlink="501080" alink="ff0000"><h1>CSE467: Advanced Logic Design</h1><h3>Ted Kehl, Fall 1996 </h3><hr><h3>Lab 4</h3><p><h3>Programming PALs and PLDs</h3><p><b>Distributed: Oct 24<br> Due: TA Option<br></b><hr><H3>Objectives</H3>After completing this lab you will know how to:<UL><LI>Program PALs and PLDs<LI>Construct and debug sequential circuits</UL><H3>I. PLD Programming</H3>Below is an ABEL file describing a simple 3-bit up-counter(upcount3.abl in the class directory). Program a PLD(instructions furnished at beginning of class) to implementthis function and use your clock generator toprovide a clock input. Use switches to provide the otherinputs to the PLD and LEDs to observe the outputs.<PRE>"Intel 5C032 PLD Pin Configuration"Input/CLK: 1"Input/VPP: 11"Inputs: 2, 3, 4, 5, 6, 7, 8, 9"Input/Output: 12, 13, 14, 15, 16, 17, 18, 19 module upcount3title 'Simple 3-bit Up-Counter with Enable and Reset'"The following line is not needed in Synario"upcount3 device 'E0320';CLK pin 1; "Clock"Q0,Q1,Q2 pin 12,13,14 istype 'reg'; "Counter Outputs"En pin 2; "Counter Enable Signal"Reset pin 3; "Counter Reset Signal" Output = [Q2,Q1,Q0]; "3-bit number" equations Output.CLK = CLK; WHEN (Reset) THEN Output := 0; ELSE WHEN (!En) THEN Output := Output; ELSE Output := Output + [0,0,1]; @const n=8;test_vectors ([CLK,Reset,En] -> Output) [.C., 1 ,.X.] -> 0; "Reset" [.C., 0 , 1 ] -> 1; "Increment" [.C., 0 , 0 ] -> 1; "Hold" [.C., 0 , 1 ] -> 2; "Increment" [.C., 0 , 1 ] -> 3; "Increment" [.C., 0 , 1 ] -> 4; "Increment" [.C., 0 , 1 ] -> 5; "Increment" [.C., 0 , 0 ] -> 5; "Hold" [.C., 0 , 1 ] -> 6; "Increment" [.C., 0 , 1 ] -> 7; "Increment" [.C., 0 , 1 ] -> 0; "Increment"@const i=1; @repeat n-1 { [.C., 0 , 1 ] -> i; "Increment"@const i=i+1;} [.C., 0 , 1 ] -> 0; "Increment" [.C., 0 , 1 ] -> 1; "Increment" [.C., 0 , 1 ] -> 2; "Increment" [.C., 0 , 1 ] -> 3; "Increment" [.C., 1 ,.X.] -> 0; "Reset"end upcount3</PRE>After you have completed the testing of this counter, modifythe ABEL program to make the counter count down as well byadding another input that specifies whether the counter shouldcount up or down on the next clock edge. Remember to modifythe test vectors appropriately.<H4>Programming PLD</H4><ol><li> Create a new project.<li> Double click on virtual device. This will bring up a dialog boxasking what kind of device you want to switch too. Choose 'Standard PLDs'and then 'EO320'. This tells Synario to create a JED file for the PLDprogrammer that programs the 20 pin PLD provided in your lab kit. <li> Create a new source from within the main Synario program. Whenasked what type of source it is, specify an ABEL-HDL file. Now enter amodule name and file name for your new ABEL file. <li> Copy from netscape (or mosaic) the source code provided above. Nowpaste the copied text into the synario editor containing your new abel file.Synario might stick some ABEL code into the editor automatically for you. For this project, simply delete that code before you paste. <li> Now you should be able to save your new ABEL file and return to themain Synario environment. Now click on 'EO320' and then double clickon 'JEDEC file'.<li> If it compiles successfully, then you should get a JEDEC- format filewith .jed suffix. Copy this .jed file to an MSDOS floppy disk.<li> To blow the fuses follow the directions given in lab by Stephen Lee<\ul><H4>Tasks</H4><UL><LI>Program the PLD to implement the up-counter.<LI>Modify the ABEL program and implement an up-down-counter.<LI>Use switches and LEDs for the inputs and outputs and yourdebounced push-button switch to provide a clock signal (that you cansingle-step by pushing on the switch).</UL><H3>II. Constructing Your Circuit</H3>You will need some PLDs, a keypad, an LCD screen, and a potentiometerfor its constrast control, Schmidt triggers ('14) and resistors andcapacitors for switch debouncing. The clock will be provided by yourpulse generator (remember that your pulser output is open-collector,so you will need a pull-up resistor, 1KOhm should work fine). And, ofcourse you'll need your trusty logic probe.<h4>Debouncing Switches</h4>The keypad has nine wires: one for each column (5 through 8), one foreach row (1 through 4), and a common wire (9) to be connected toground (this is the common connection for all the switches). (If youhave a 3-column keypad, then there are only 3 column wires and 8 wirestotal.) When a key is pressed the corresponding column and row wiresare connected to the common signal (see the figure below). Therefore,the keypad is called a 2-of-8, 2 of the 8 wires will be active lowwhen a key is pressed, the others are pulled high through resistorconnections to 5v.To debounce the type of switch in the keypad (single-pole single-throwor SPST) will require a special analog circuit consisting of aresistor, capacitor, and a Schmitt trigger (`LS14). Connect pull-upresistors and capacitors to the eight outputs of the keypad as shownin the figure on the top of the next page. The sizes of these devicesshould be chosen so that the RC time constant is approximately 50ms,this should be enough to eliminate the bounce of even theseinexpensive keypad switches. Test your keypad with your logic probe.<p><img src="keypad.jpeg"><p>When a key is pressed, two switches are closed thereby shorting thetwo capacitors to ground and very quickly discharging them. Thismakes the output of the Schmitt trigger inverters immediately go high.If the switches momentarily disconnect, the capacitor will startrecharging but only slowly due to the large RC time constant. If thetime constant is longer than the bounce time then there won't beenough time to charge the capacitor enough to trip the Schmitt triggerand the output will stay high. The internal hysteresis of the Schmitttrigger will prevent it from switching again until the input gets veryhigh. Once the switch is let go, there will be enough time and thecapacitor will eventually charge to 5v and the output of the Schmitttriggers will be low. Also, note that the row and column wirescorresponding to the depressed key may not change value at the sametime.<h4>LCD Details</h4>Documentation for the LCD display was distributed in lab.There is also an excellent <a href=http://www.cen.uiuc.edu/~cburian/lcd.doc>FAQ</a>describing your LCD module.There is an accompanying figure(<a href=http://www.cen.uiuc.edu/~cburian/chset2.gif>Character set</a>.)Also, an article on the physics of LCD displays(<a href=ftp://ftp.ee.ualberta.ca/pub/cookbook/faq/LCD2.doc>text file</a>.)This collection is likely more completeand lucid than the data sheet.Details of other partsare available from the TTL data book or onlinefrom <a href="http://motserv.indirect.com">Motorola's Data Book Server</a>.<P><p><img src="first.jpeg"><p>You should construct your circuit in phases. First, build the keypaddecoder and synchronizer, then the transmitter. ON the receiving end,first build that portion of the FSM that will reset the display andprint some character (possibly hard-wired, initially), and finally thetransmitter. Make sure the transmitter is working before plugging themtogether. (You can see the values being transmitted if you run theclock at 1Hz.)You should be able to make some progress this week and perhaps evencomplete the circuit. We will cover how to use the logic analyzer todebug sequential circuits in the next lab. If you are having realproblems, you might want to wait until then.<HR><H3>Hand In: (DueTA Option)</H3><OL><LI>Demonstrate your up-down counter using switches and LEDs and haveyour TA sign your ABEL listing.<LI>ABEL program listing, test results, equations and PLD pinout.</OL></body><address><hr>ted@cs.washington.edu</address><p></html>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -