Overview

ATmega2560 CPLD Development Board is an Arduino-compatible CPLD, or Complex Programmable Logic Device development board based around Altera (now Intel) Max 7000S series CPLD, and Microchip ATmega2560 microcontroller.

The basic operating principle is that every CPLD IO pin can be accessed with the on-board, Arduino-compatible ATmega2560 microcontroller.

This board was designed for learning CPLD development, to verify CPLD designs, and to learn how to interface with CPLD devices. So as a learning platform this is an invaluable, easy-to-use tool.

CPLD

Comes with EPM7128SLC84-15N. Board also supports Microchip ATF1508 but that CPLD cannot be programmed with the included USB Blaster, but requires a Microchip programmer that is not included.

While Max 7000S (EPM7128SLC84-15N) supports split-voltage operation, this board is single 5V only.

Notice that the CPLD has finite number for how many times it can be programmed - approximately 100 times. You may wish to purchase additional devices, which are available as option to purchase.

You can use Quartus II v13.0sp1 to write Verilog or VHDL, and you can use it, or for example ModelSim to simulate your designs before committing to programming it on to the CPLD.

Clock sources

The clocking options are extremely flexible. On-board there is a 16MHz oscillator that provides clock for the ATmega2560. This same clock can be used to clock the CPLD, allowing for synchronous operation via a simple jumper configuration.

The CPLD may also be clocked from different clock source: on-board is an unpopulated footprint for an SMT oscillator, and also a header for square, metal can type oscillator. With jumper configuration one of these clocks can then be connected to the CPLD clock input. This configuration is documented on the silkscreen.

Additionally, the Max 7000S has a third clock input which is available at the header, allowing for a total of three clock inputs.

Programming

ATmega2560 / AVR programming

Comes with an Arduino bootloader burned on to the ATmega2560, making the board basically an Arduino Mega, and as such, programmable from an Arduino IDE or from a PlatformIO with Visual Code, for example.

It is also possible to program the ATmega2560 using the AVR ICSP, which are available at the headers (PB1, PB2, PB3; RESET# at JP5).

CPLD programming

Comes with USB Blaster that is used to program the CPLD from Quartus II v13.0sp1. USB Blaster plugs into the JTAG header.

Schematic and support

Schematic, board layout and support is available for educational institutions with purchases of at least 5 boards.

Every board, however, comes with a pin map list that translates between the CPLD pins and the ATmega2560 pins. This pin map is output to the serial port, so before reprogramming the ATmega2560, make sure to grab that pin map from the serial port. Just connect to a correct serial port at 115200 baud.

References

• Quartus II v13.0sp1

Errata

v3.4.4.0

Y3 silkscreen marking

The connector for a metal can style crystal at the upper left corner on the top side of the board is incorrectly labeled as Y2. Correct label for the device is Y3. Note this when using the operating instructions printed on the silkscreen of the board.