Pluto, Pluto-II and Pluto-3 FPGA boards

The Pluto boards are FPGA development boards that plug into a PC's serial port.

To purchase a board, go to the KNJN RS-232 development boards shopping page.

Characteristics

Board	Pluto	Pluto-II	Pluto-3
FPGA (vendor page)	EP1K10	EP1C3	EP2C5
Datasheet (PDF)	ACEX 1K	Cyclone	Cyclone II
Logic cells	576	2910	4608
IO pins	41	51	65
PLL	No	Yes	Yes
External clocks	up to 2	up to 4	up to 4
Boot-PROM	No	1 Mbits	4 Mbits
On-board oscillator	25MHz	25MHz	25MHz
DIL8 oscillator header	No	No	Yes
Push-button	No	No	Yes
JTAG header	No	No (1)	Yes
LED(s)	1	1	2
Flashy ready	Flashy	Flashy	FlashyD
Dimensions (mechanical drawing)	58x28mm	58x28mm	58x41mm

(1) Pluto-II JTAG signals can be accessed but require manual soldering of 6 wires to the board.

• Easy to use - controlled from a PC's serial port.
• Small form factor - go into a "solderless-breadboard" for experiments, or used as motherboards or daughterboards for other projects.
• Few on-board peripherals, most IOs available to connect external peripherals.
• Built-in voltage regulator, simply use a common DC adapter as power supply.
• Flashy boards compatible, to build an acquisition system or digital oscilloscope.
• Built-in "secondary" connector.

FPGA configuration

How to connect the boards to a PC

The Pluto boards connect to a PC's serial port.
The serial port has two purposes:

1. It is used for FPGA/boot-PROM configuration.
2. Once the FPGA is configured, it is used to communicate with the PC (you can write a PC software that give orders to the FPGA, for example).

The secondary connector

This is a small connector found on one side of the Pluto boards. This connector has only 4 pins (2 powers and 2 IOs) so only serial communication peripherals can be attached. For example:

• I2C peripherals
• LCDs and LED displays with serial interface

Here's Pluto-II connected to a color graphical LCD through the secondary connector.

JTAG

JTAG allows using Quartus-II's built-in JTAG support (including the SignalTap II logic analyzer).
Note that to use JTAG, a separate JTAG cable is required, like a ByteBlaster (or compatible cables, like these).

Flashy

The Pluto boards are compatible with the Flashy ADC daughterboard. Pluto-3 is also compatible with FlashyD (two channels).

See here how to build a simple digital oscilloscope.

What files do you receive with the Pluto boards?

• Board documentation (view online here) (PDF)
• FPGAconf configuration software (Windows EXE)
• FlashyDemo (FPGA bitfile + GUI)

• LED (HDL source code)
• Music (HDL source code)
• SerialRxTx (HDL + C source code)
• Pong VGA (HDL source code)
• FlashyMiny (HDL + C source code)

To purchase a Pluto board

Go to the KNJN RS-232 development boards shopping page.