CSE370 Laboratory Assignment 8
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Design Project
Distributed: 26 November 2003
Due: 10 December 2003
Objectives
In this laboratory assignment you will build an RS232 to LCD pipeline (see project description). You are
provided with a schematic and Verilog files for all the modules. Two of the modules (MainController and
InitDecoder) have incomplete Verilog descriptions that you must complete. You will then synthesize these
two parts into PALs and wire up the entire circuit on your XLA5 board connected to a PC running
HyperTerminal to provide the characters to display and send them over the RS232 cable.
HyperTerminal
The screen shot below shows how to configure HyperTerminal.
Note: You may experience a peculiar problem with HyperTerminal that the MSB of the character changes
when you repeatedly press the same key on the keyboard. If this happens to you, here is the fix.
Reconfigure HyperTerm as its settings are causing the problem. When you run HyperTerm you should see
"4800 8-N-1" at the bottom of the window, as shown in the red circle in the figure. If it instead says
Auto-Detect you need to stop the session by clicking on the Disconnect button (circled in green) and goto
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the File menu, and Select properties. Click on configure. Ensure that the settings are correct and also
make sure that you click the apply button. (If apply is greyed out, make a change then change it back then
click apply). Now hit the Connect button and check to see if 4800 8-N-1 comes up.
Design Files
To create your own design for this project, load the following files into Active-HDL:
Schematic
Sender.v
SerialBuffer.v
MSI377.v
MSI244.v
drop_a_bit.v
MainController.v
InitDecoder.v
Documentation for the LCD module is available here or from the manufacturer's web page.
You will need to set the contrast for the LCD screen. For this, we have to apply a voltage at the Vo pin
that we can obtain using the voltage divider circuit shown in the figure below. This circuit will generate a
voltage for Vo of approximately 1/(1+4) of VCC or .2 of 5 volts or 1 volt. If you look at the LCD screen
specs you will find the location of the Vo pin. In your kit we have included a 3.9K ohm resistor and a 1K
ohm resistor. You can determine the resistance value of a resistor by the color coded bands on the resistor
(see explanation of how the color coded system works and an automated calculator).
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Notes
1. This laboratory assignment is linked to the last written assignment and you can work with your lab
partner on both together. In fact, this is recommended. You will turn in one copy of the written
assignment and have this laboratory assignment checked off for both of you.
Review of PAL Programming Method
Place the PAL into the programmer as close to the lever as possible (shown the in figure below where
your PAL fits into the red box.)
NOTE the location of PIN 1. This means the notch on top of the PAL must be place opposite from the
lever.
Programming Steps
1. Erase the PAL
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2. Program the PAL
3. Verify the PAL
If ANY of these steps fail try your other PAL. Contact the course staff to help you deal with failures in
these steps.
Please be careful with the programmers. Take the time to ensure that you are putting the chip in correctly
and that you are following the steps correctly. Refer back to the tutorial for further details.
Creating a wiring file for your PAL
To create a wiring file for your PAL you need to create your own CTL file. Refer back to laboratory
assignment 7 for an example on proper syntax. Essentially you are creating an attribute by concatenating
the various wiring assignments ending the attribute with a semicolon. One important thing to note is that
the following 4 items should have the exact same name or you control file might not work.
1.
2.
3.
4.
The Verilog File (extension .v)
The Verilog Module
The Control File (extension .CTL)
In the attribute declaration line in the CTL file (e.g attribute pin_numbers of [verilog
module]:module is)
Tasks
1. Start by connecting the serial cable from the PC to the connector on the XLA5 board. To do this,
you will need to add a "null modem" and a "gender changer" between the XLA5 connector and the
end of the cable. Make sure to do this. Otherwise, you will not receive characters on to your board.
Make sure to keep the null modem and gender changer with your kit, that is, remember to remove
them when you unplug your XLA5 board.
The sender module of the project schematic is implemented by the PC and the serial_buffer module
is already loaded into the FPGA (see schematic). We'll need LEDs connected to the "received" and
"charRcvd" outputs of the FPGA ("received" is already connected to LD7, wire O2 to one of the
other LEDs) and a switch connected to the "displayed" input of the FPGA (O3). The system already
has a reset, use push-button BTN1 to indicate a reset. The LD6 output of the FPGA makes reset
available after it is synchronized and debounced so that you can use it in the rest of your circuit (it
is also connected to LD6 for easy viewing). Power-up the board and start HyperTerminal on the
PC. Send a character over the RS232 cable with HyperTerminal by typing a character on the PC
keyboard. (Make sure to configure HyperTerminal correctly by following the instructions above.)
You should see the "received" LED light up after you type a character on the keyboard. What is the
value of charRcvd? Shift out the character one bit at a time by using BTN4. You'll want to look for
a start bit followed by the 8-bit ASCII code of the character and then a stop bit. Did you see the
code for your character delivered serially on "charRcvd"?
2. You will now wire up your part of the circuit using the provided schematic as a guide. By now,
you'll have completed the design of your two PALs and verified their operation in the simulator.
Note that the '244 and '377 modules were set up to match the physical parts pin for pin. You'll have
to decide on your own pin assignments for the PALs. The "drop_a_bit" module does not exist
physically. It simply connects some wires to make the '377 into a shift register. You can realize it on
your protoboard just with wires - no chips needed. The display module can be plugged directly into
your protoboard. Make sure to leave room to connect to the 13 pins (PWR, GND, 8-bit data, RS,
RW, and E).
Verify the operation of your circuit a piece at a time. Compare against your simulation waveforms
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as you single step. Demonstrate it to the TAs by sending a few characters to the display. Also,
demonstrate any extra credit commands you may have implemented.
Comments to: cse370-webmaster@cs.washington.edu (Last Update: 12/09/03 )
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