Author: Jacinda Clemenzi - Last Updated: December 20, 2001
Last Revised: D. E. Troxel - January 12, 2003
The purpose of this guide is to provide a tutorial that will help you to become familiar with how to use the software provided by Altera to edit VHDL, simulate designs, and program the FLEX 10K FPGA devices. It will be assumed that you have a basic understanding of VHDL.
Altera provides a software package for programming their devices. This package is called MAX+plus II and can be accessed from the 6.111 locker from any Athena Sun OS workstation. In addition MAX+Plus II can be run from Windows 98 under vmware on the Athena Linux PCs in the Digital Lab. To run MAX+plus II on a Sun Ultra 5, type:
athena% setup 6.111
athena% max2win &
MAX+plus II is a fairly complete software package. It provides an editor, compiler, programmer, waveform generator, and simulator. Each of these functions can be chosen from the MAX+plus II menu option. This guide gives a walk-through of the different steps necessary to program a device. At the end is a step-by-step tutorial with an example project.
Starting a Project
Working with VHDL Files
Configuring the Device
Compiling
Viewing the Report
Assigning Pinout
WARNING - BURNOUT
Simulation
Programming
A Simple Example: An 8-Bit Counter
Appendix: Differences between MAX+plus II and Warp
A project consists of all the files necessary to program one device. MAX+plus II works with one project at a time. When you first open MAX+plus II you will have to create a project. The name of the project must be the name of the top level VHDL file. The recommended method for starting a new project is to open an existing top level VHDL file or create a new one through the File menu option:
| File > New... |
or
| File > Open... |
Then set the name of the project to the current file by doing the following:
| File > Project > Set Project Name to Current File |
It is easy to change the name of the project and top level file at any time in the future.
All of the components you call in your top level VHDL file need only to be in the same directory for the compiler to find them.
When you open MAX+plus II next time, it will automatically load the last project.
MAX+plus II provides an editor that uses color coding much like Emacs. When you open a VHDL file in MAX+plus II it is the default editor. You can access it directly through the MAX+plus II menu option. You may use any editor to modify files. Of course, if you use the Windows 98 version you may want to use dos2unix or unix2dos as appropriate.
Once you have defined a project, you will need to configure the device.
| Assign > Device... |
Now select the FLEX 10K device from the pull-down menu. This will give you a number of selections in the Devices scroll menu. For this tutorial choose EPF10K10LC84-3. (If you later use the right hand chip, choose EPF10K70RC240-2.) From this same window click the Device Options button. From the pull-down menu next to the keyword Configuration under Device Options select EPC2LC20.
Compile the code by selecting the compiler from the MAX+plus II menu option. Before you start the process you should select which version of VHDL syntax you would like the compiler to use. To be consistent with the VHDL code used for programming Cypress CPLDs, you should select the 1993 version:
| Interfaces > VHDL Netlist Reader Settings |
Now select the VHDL 1993 option.
To compile the file click Start. The process will take some time, especially fitting it to the device. Be patient. Any errors or warnings will appear in a window that pops up during the process.
Several files are generated by the fitter after your project is compiled. The two most useful files are the report file and pinout file. The report file will include the pinout close to the bottom.
The report file is project_name.rpt
The pinout file is project_name.pin
Now that you have compiled the project once and let MAX+plus II assign the first pinout, you can set it so it remains constant in three ways.
First, you can directly edit the configuration file project_name.acf. If you edit the configuration file then you will have to set the project name again for the changes to take effect.
Second, you can use the graphical interface provided by MAX+plus II to modify this file:
| Assign > Pin/Location/Chip |
Enter the name of the node and the corresponding pin assignment. Be sure to select the Add button after each assignment.
The last and easiest option to assign the pinout is to let MAX+plus II back assign the pin numbers automatically to the configuration file for the project:
| Assign > Back-Annotate Project... |
Select the Chip, Pin & Device option.
A number of students have burned out FPGAs. The FPGAs that have been fried are the 10K70 (the right hand one). The 10K70 is surface mounted and it is expensive to replace. In addition, the pc board is often damaged in trying to replace the 10K70. We have a limited number of pc boards!
Altera states that unused pins MUST be unconnected. This is only possible for the pins connected to the /AD bus if you do not connect anything to the /AD bus. This means that you must not have any wires in /AD0-31 for unused pins to the Altera FPGA and also that you must not have NUSW grounded if any unused pins on the Altera FPGAs are connected to /AD16-31. In other words, remove the jumper which connects NUSW to ground.
It is ok, perhaps even desirable, to have NUHEX grounded and /CLK wired to /LHEX and /HHEX so that the hex leds always display the /AD bus.
Another way to avoid these contention problems is to use all pins connected to the /AD bus. You, of course, could use them as inputs to the FPGA. If you wish to use them for other purposes, then you must explicitly declare them as outputs and explicitly tristate them.
Unused pins must be specifically listed in the top level entity and specifically tristated. See the example files tristate.acf and tristate.vhd in the directory /mit/6.111/altera/tristate.
If in doubt, read the handout that describes the kit wiring. If you cannot find it, then look for it on the web page. All of these /AD bus pins must be used as inputs, outputs, or specifically tristated. In addition, all pins that are connected to a 50-pin connector (see below) should be used as inputs, outputs, or specifically tristated.
Please use the 10K10 (on the left) until you are familiar with the use and programming procedures for Altera FPGAs. This device is in a socket, and at least we can replace it if you burn it out.
MAX+plus II provides a simulator and waveform generator for verifying that your code performs the way you expect it to. To simulate your design, you must first create a waveform file that includes input waveforms and specifies which output waveforms to watch. Do this by using the waveform editor:
| MAX+plus II > Waveform Editor |
Now select the input and output nodes from your project:
| Node > Enter Nodes from SNF... |
This will allow you to select multiple nodes at once by highlighting the names and clicking the arrow button to move them into the box on the right. Click OK to add these nodes to the Waveform Editor. Now you will want to define the input waveforms by selecting each waveform and using the toolbar along the left.
Set your maximum simulation length by:
| File > End Time |
Once you have done this be sure to save as project_name.scf.
Now you are ready to run the simulator.
| MAX+plus II > Simulator |
Deselect all options if any are selected and press Start. You can view the results in the Waveform Generator. If you have already closed this window, then click Open SCF.
Set up your lab kit next to a computer with a BitBlaster or ByteBlaster programmer in the Digital Lab. Be sure to plug the programming cable into the programming port next to the chip you wish to program. Each port programs the chip closest to it. Be sure to align pin 1 by matching the arrows when plugging in this cable. The red stripe should be on the left. Power on your kit. Now open the programmer from MAX+plus II:
| MAX+plus II > Programmer |
Program your FPGA by using Altera's MAX+plus II software.
If this is the first time that you are using the programmer, a hardware configuration window will appear. Likely the appropriate hardware options will be displayed on the computer case. If not, see the beginner's guide or the handout ``How to Use Max+plus II''. You can edit the hardware configuration at any time as follows:
| Options > Hardware Setup... |
To speed up the programming process, you should turn off the automatic blank-check and verify. Select the following menu option:
| Options > Programming Options... |
A pop-up window will appear. If any of the options are selected, de-select them. Click OK.
Now you have to specify the programming method. Make sure that Multi-Device JTAG Chain is selected from the JTAG menu.
| JTAG > Multi-Device JTAG Chain |
If this is the first time that you have used this option, the configuration window will pop up automatically. From the Device Name pull-down menu select EPC2LC20. Click Select Programming File... and choose the file called project_name.pof. Click Add. Click OK.
Now you are ready to program the device. To do this, click Program from the main programming window. Programming will take a while. When the programmer is done, it will return a ``Programming Successful'' message.
You will have to turn the power to your kit off and on to get the
new program to load into the FPGA.
This section will walk you through all the steps above with a short tutorial to create a simple 8-bit counter. The 8-bit counter has two modes: user mode and clock mode. In the first mode, the counter will increment each time you push a trigger switch. In the second mode, the counter will increment on each rising edge of the clock signal. A reset signal will allow the counter to be reset to zero.
This section has been divided into two parts because there are two implementations in VHDL of the 8-bit counter. The first implementation should be straightforward and understandable from the notes in the VHDL file. After completing this part you may find that the counter output is unreadable when in clock mode because the clock is too fast. The second implementation divides the clock signal by a power of two to produce a slow_clk signal, which is counted instead of the clock signal.
Part I
The steps are listed here with a little explanation. Please see the previous sections for more information.
athena% setup 6.111
or, under Windows 98, click on the icon.
li>In the pop-up window, select EPC2 from the Device Name pull-down menu and the click Select Programming File... Choose the file called counter8.pof. Click Add. Click OK.
athena% mkdir 6.111.example
athena% cd 6.111.example
Copy the example files from the web or the 6.111 locker to your directory:
6.111% cp /mit/6.111/altera/beginner/counter8.* ./
Then change the mode so you can write to these files.
6.111% chmod 644 *
Then start MAX+plus II:
6.111% max2win &
Part II
The second part of this example implements a slightly more complicated version of the 8-bit counter from Part I.
You should already have a directory for your work from Part I. The files you will need for Part II are slow8.vhd and slow8.acf. The file slow8.vhd is the VHDL file, and slow8.acf is the configuration file that sets the device, configuration device, and pinout.
Follow the same steps that you followed in Part I to program and test the device. The functionality on the 6.111 kit should be the same as the example in Part I except that the counter will visibly count when in clock mode.
Appendix: Differences between MAX+plus II and Warp
MAX+plus II is the software provided by Altera for writing VHDL, compiling and programming their FPGAs. Cypress provides a similar tool for their CPLDs called Warp. If you already have experience with Warp, you may be interested in the specific differences between the two programs.
VHDL Libraries
Unlike Warp, Altera uses the standard IEEE libraries for
arithmetic operations with the std_logic_vector type. In Warp, the
necessary library is work.std_arith. In MAX+plus II, the standard
libraries are ieee.std_logic_arith, ieee.std_logic_unsigned, and
ieee.std_logic_signed. You probably want the latter, especially if
you want to subtract.
Working With Projects
In MAX+plus II projects are handled a bit differently. The project
is defined and set to the same name as the top level file. Each VHDL
file must have the same name as that of a component defined in
them. Furthermore, all components referenced by a top level VHDL file
must be in the same directory as the top level file.
Assigning Pinout
Unlike Warp, the pinout can not be specified in the VHDL file. The .acf file holds all the device configuration information including pin assignments, device, configuration device, and logic block assignments. This file can be edited directly, but Altera also provides a way of editing each of these options through the graphical user interface.