Altera DE1

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The Altera DE1 is an Evaluation/Educational FPGA development board made by Terasic in Taiwan.

It is one of the best off the shelf boards for Retro FPGA work due to it's feature set, it's price and popularity.


Quoting from the Terasic Website:-

  • Altera Cyclone II 2C20 FPGA with 20000 LEs
  • Altera Serial Configuration deivices (EPCS4) for Cyclone II 2C20
  • USB Blaster built in on board for programming and user API controlling
  • JTAG Mode and AS Mode are supported
  • 8Mbyte (1M x 4 x 16) SDRAM
  • 4Mbyte Flash Memory
  • 512Kbyte(256Kx16) SRAM
  • SD Card Socket
  • 4 Push-button switches
  • 10 DPDT switches
  • 8 Green User LEDs
  • 10 Red User LEDs
  • 4 Seven-segment LED displays
  • 50MHz oscillator, 24MHz oscillator, 27MHz oscillator and external clock sources
  • 24-bit CD-Quality Audio CODEC with line-in, line-out, and microphone-in jacks
  • VGA DAC (4-bit R-2R per channel) with VGA out connector
  • RS-232 Transceiver and 9-pin connector
  • PS/2 mouse/keyboard connector
  • Two 40-pin Expansion Headers
  • DE1 Lab CD-ROM which contains many examples with source code

Getting Started

We have a getting started guide here :- Altera DE1 Installation guide

At the time of writing the Zet used the resources of the DE1 are used as follows:-

  • PS/2 is the Keyboard input
  • VGA is the Display Output
  • SW0 Slide Switch acts as a Reset Switch (Up to Reset)
  • SW1 Select the boot device (Down for SD Card, Up for Floppy (Flash) Boot)
  • Seven Segment Display shows the upper 16 bits of the Program Counter in Hex

Serial Communications

The Serial port of the DE1 is a simple 3 wire one with just Ground, Transmit and Receive. It has a Female connector and a Modem style pin out so needs a 1-1 Male to Female DB9 cable. This is the same as a 9 Pin Extension Cable. It does not need a laplink (Crossover) style cable and due to the sex of the connectors such a cable will not plug in anyway!