CoolRunner-II CPLD breakout board

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Project Summary
Name: CoolRunner-II CPLD breakout board
Buy it: Get one for $15 at Seeed Studio
Price: $15
Status: Test production
Manufacturing: Shipping
Forum: CoolRunner-II CPLD breakout board Forum
Xc2c64a cpld breakout-vib.jpg


Ever get stuck choosing the right logic chip combination or voltage level translator? Give up the hunt and create your own custom logic chip. CPLDs can give you the logic you need, with the pinout you want, while saving board space and board revisions.

The CoolRunner-II XC2C CPLD has two separate banks of pins that can operate at different voltages, internal pull-up resistors, and pin keepers. This development board from Dangerous Prototypes will help you build your first custom logic chip using simple schematic entry, Verilog, or VHDL.

  • XC2C64A CPLD with 64 macrocells
  • On-board 1.8volt supply for the core
  • On-board 3.3volt supply for pins
  • Separate pin banks can be operated at different voltages (1.2volt to 3.3volt)
  • Selectable 1.8volt, 3.3volt, and external supply for each pin bank
  • LEDs for output
  • Push button for input
  • Populated JTAG header
  • Unpopulated oscillator footprint on bottom
  • Easy to program with the Bus Pirate and Bus Blaster
  • Pre-programmed with LED inverse toggle demo
  • Open source (CC-BY-SA)

Available for $15 at Seeed Studio.

Contents

Overview

XC2C64A-CPLD-Breakout .png

Hardware

Cct-XC2C 64a-cpld-breakout-v1a.png

Click for a full size schematic image. Schematic and PCB were designed with the freeware version of Cadsoft Eagle, download the latest project files from our Google Code project SVN.

CoolRunner-II XC2C64A

XC2C64a-datail.jpg

The XC2C64A (U1) is a 64 macrocell CPLD with two separate IO banks for voltage translation. It is one of the smallest CPLDs made by Xilinx, and is readily available from Digikey for around $2.65.

The CPLD core requires a 1.8volt supply to each VINT pin. This supply is provided by an on-board 1.8volt regulator.

The IO pins are divided into two banks that each operate from a separate supply of 1.2volts to 3.3volts. An external supply can be connected to either IO pin, or place a jumper on the V1 and V2 pins to select the on-board 1.8volt or 3.3volt power supply.

Each supply pin has a 0.1uF capacitor (C1,C2,C3,C4).

The JTAG programming pins are brought to header JT. The JTAG interface is powered by the 3.3volt core supply.

Power supply

A 1.8volt regulator (U2) powers the CPLD core and (optionally) the IO pins, which a second 3.3volt regulator (U3) is available to power the IO pin. C5, C6, C7, and C9 are 3.3uF capacitors on the regulator supply and output.

Both regulators are supplied through pin V+. The supply can be up to 5volts. Up to 100mA is available from the 3v3 pin.

LED PWR lights if the power supply is active.

Buttons and LEDs

XC2C64a-IOfeatures.jpg

Two LEDs (D1, D2) and a push button (PB) are included for a little user IO.

LED D1 and D2 source current from the CPLD. Generally, designers sink current from CPLDs and FPGAs - the chip connects the LED to ground instead of power - because many parts can sink 20mA but only source a few. On this chip, however, the maximum current is a paltry 4mA for both source and sink. The LEDs have 2K resistors (R2,R3) that keep the current at an acceptable 2mA.

A push button (PB) provides a way for user input. Resistor R1 is a pullup for the button, it is not populated because the CoolRunner-II chips have internal pull-ups on each pin.

Pinout table

Pinout
BANK2 DescriptionDescription BANK1
GND Ground connection Ground connection GND
V+ Supply voltage (max 5volts) 3.3volt output (max 100mA) 3V3
V2Bank 2 IO external supply (1.2-3.3volts)1.8volt output (max 50mA) 1V8
18Push buttonBank 1 IO external supply V1
19 16
20 14
21 13
22 12
23 8
27 6
28 5
29 3
30 2
31 1
32 44
33 43
34 42
36 41
37 40
38LED D2LED D1 39

PCB

Pcb-xc2c64a-cpld-breakout-v1a.jpg

We used the freeware version of Cadsoft Eagle to make the schematic and PCB. Download the latest board files from SVN.

Partslist

Brd-XC2C64a-cpld-breakout-v1a.png

partlist
Parts Quantity Value Package
C1,C2,C3,C4 4 0.1uF C603
C5,C6,C7,C9 4 3.3uF Tantalum SMC_A
D1, D2, PWR 3 LED LED-805
JTAG 1 0.1” Pin header 1X06
PB 1 SMD button, small TACT_SWITCH_SMALL
R2,R3,R4 3 2K R603
U1 1 XC2C64A_VQ44 VQ44
U2 1 1.8volt LDO voltage regulator 100mA SOT-23-5
U3 1 3.3volt LDO voltage regulator 150mA SOT-23-5
V1,V2 2 0.1” Pin header 1X03

The latest sources and distributors are in the master partlist. See something missing? Please let us know.


Q1 on the bottom of the PCB is for an optional 3.3volt oscillator. It feeds into a global clock pin. Some suitable values are:

Programming

Development and programming tutorials are on the main CPLD page.

Get one!

Xc2c64a cpld breakout-vib.jpg

You can get one for $15, including worldwide shipping.

Your purchases at Seeed Studio keep the open source project coming, we sincerely appreciate your support!

Resources

License

  • CC-BY-SA