Tarfessock 1

Tarfessock 1

Tarfessock 1 is a Cardbus/PCMCIA style FPGA development board. It can also be used as a support tool for laptops giving them a programming capability for Xilinx FPGAs and also RS232/RS485 serial communications for microprocessor support. Laptop or PC host features like hard disk and Ethernet can also be used to expand the functionality of Tarfessock 1. Tarfessock 1 can also be used as FPGA co-processor.


Rev 1.1 Tarfessock 1 is now available.


Tarfessock 1 has two Spartan-3E FPGAs.

Device 1 is a Xilinx Spartan-3E XC3S250E-4FTG256C FPGA and contains the Cardbus, Programming, A/D, DAC, Charge Pump and serial interfaces and is generally not intended as a customer development device. However customers may use device 1 as a development target if they so wish.

Device 2 is a Xilinx Spartan-3E XC3S1200E-4FGG400C FPGA and is the main development device for customers. It is also possible for us to fit a XC3S1600-4FGG400C as an alternative part.

Cardbus Interface

Device 1 supports this interface. It is our intention to supply Tarfessock 1 with a Target only function pre-programmed in FPGA device 1. Currently we are shipping without this interface programmed. Contact us if you need this preprogrammed.

RAM Memory

Device 2 has 512Mbit, X16 , DDR2 RAM connected to it.

Flash Memory

Device 1 has a 16 Mbit SPI Flash memory connected that is used for device 1 configuration. This device can also be used for MicroBlaze code storage or as a programming source for device 2. This device is also used to store device 2 configuration setup allowing configuration of this FPGA to come from a number of sources including remote or local hard disks in the host computer.

Device 2 also has a 16 Mbit SPI Flash memory connected. This can be used for configuration of device 2 or as a code storage etc.

RS232 Serial Interface

Device 1 supports a RS232 serial interface that can be used to support external target microprocessor development or as an alternative connection to a PC.

Internal Serial Interface

Device 1 has wired connections to device 2 to support a serial interface (TTL levels) for MicroBlaze development in Device2.

RS485 Serial Interface

A 4ch RS485 interface is supported by device 1. Each channel is half duplex with individual direction control.


A 8ch, 200 KHz , A/D is support be device 1. Device 2 or hosting Laptop/PC can read measured values from device 1.


A 4 channel DAC is supported by device 1. Output values can be set by host Laptop/PC or device 2.

Programming Interface (O/P)

Device 1 supports a combined Parallel Port + Cable III type interface to allow programming of an external FPGA target. This function can also be redirected to act as a programmer of device 2 offering a seamless connection to Xilinx™ Impact™ and Chipscope™ tools. The external JTAG interface will be capable of running at 3.3V, 2.5V and 1.8V programming levels. It will also be 5V tolerant and we expect capable of handling 5V JTAG chains (only 3.3V drive on signal levels).

General I/O + Expansion

Tarfessock 1 has one 120 way edge connector for outside world connection. This connector contains all programming and serial interfaces listed above that connect to the outside world. In this connector there are also approximately 70 5V tolerant general I/O. A switched 3.3V, 0.5A output is available to power external logic on the connector. The connector also supports presence detection and identification (SPI) of externally connected boards. The identification interface has permanent power available (3.3V, 100 mA) to allow identification before powering up main parts of external logic using the switched 3.3V output.

Programming Interface (I/P)

I/P JTAG programming of device 1 and device 2 is supported by external programming cables. Programming of the SPI Flash for device 1 can also be supported using these cables.

Custom breakout boards, builds and derivative products of Tarfessock 1 will be supported. Please contact our board sales team with any enquiries.