Cyclone IV FPGA Development Board

Intro

My favourite thing about ebay is that it has a wide variety of development boards which provide great functionality at prices far lower than branded products.  Looking for an FPGA board I was very excited when I saw this one.

It has a great specification:

FPGA core board: Power input DC5V FPGA:EP4CE10F17C8N SDRAM:256M SPI FLASH: 64M 50 MHz CLK input  Bottom board: PC PS/2 port VGA port ,can display picture or video, 16 bit 65536 colours SD card LCD12864/1602 ,can display number or English character LCD TFT ,can display number or English character, or video LED 7seg display 1x8, can display number LED 1X8 COM port 8X8 LED dot matrix 3X3 key input pad 1X4 key input switch 1X8 input ADCTLC549, you can analogue signal acquisition DAC7512, digital signal to analogue signal IR input DS18B20 temperature sensor

So three days later we have lots of inputs and outputs to play with.
In fact the FPGA board is detachable so one could theoretically use all the board IOs for other purposes.

I experienced problems initially as my usb blaster programmer turned out to be a clone and I had to install old WIN7 unsigned drivers to make it work.  Once I was able to load software the board was great.  The vendor provided Quartus programs to test the main features and it was a pleasure to load and run them so that I could be sure my subsequent efforts utilised working hardware.  Update: Life became much easier when I bought a real usb blaster (£16 instead of £6), which works perfectly.

MAX1000 FPGA

I have always been somewhat in awe of FPGAs and nervous of the challenges they present.  Recently, in the March/April edition of Elektor, I saw an instructional article to create a processor on  an Altera/Intel MAX1000 which reminded me of a study of Computer architecture, based on Nand2Tetris.com, which I enjoyed immensly .  The web-site (and book) leads you through all the important steps involved in building a computer starting from a collection of Nand gates and ending with  processor, assembler, compiler and Operating System to run your own programs.
Nand2tetris provided a hardware simulator based on building an increasingly complex hierarchy of components but naturally enough it was too slow to deal with running non-trivial programs.

I went through the following stages to find out more.

1) Purchase a $30 MAX1000 from Arrow Computers

2) Elektor 8080 + Small-C compiler part 1 : LED pattern

Following the instructions in Elektor magazine I built the 8080 simulator FPGA program and was able to run the C program which generates a MAX1000 LED pattern.

3) MAX1000 User Guide Tutorial : LED counter

When delivered the MAX1000 runs an LED counter program, using the tutorial I was able to recreate and download to the FPGA.

4) Quartus, Hello World : NAND gate LED

I wanted to write the simplest possible program and decided on a Nand gate.  Unfortunately only one button is easily available on the MAX1000 so I implemented a NOT gate instead.  When a button is pressed an LED goes out.
This exercise simplified technical work into two tasks:
a) a very simple HDL program to implement a NOT gate.
b) assignment of two MAX1000 pins to a button and an LED

5) Altera NIOS II Hardware Development Tutorial

NIOS II is an FPGA microcontroller developed provided by Altera.  A tutorial is provided which goes through a significant number of steps to build the solution.  It helps you become familiar with the Quartus Prime environment and the specific MAX1000 hardware.

By the end of this investigation I had a very basic idea how to use Quartus Prime and a MAX1000 board.  Clearly 1 usable button and 8 LEDs are insufficient to maintain an interest in programming.  Rather than adding my own devices by breadboarding the MAX1000 and various peripherals I decided to buy a board which already has them built in.