University of Heidelberg Institute of Computer Engineering

HT-Core Lattice SCM port

The Computer Architecture Group (CAG) is proud to announce the availability of the HT-Core for the Lattice SC/M family of FPGA devices. The core implements a complete 16-bit HyperTransport cave device and can be mapped onto an Lattice SC/M FPGA. The HT-Core is released under an open-source license.

Porting of the Core to the Lattice architecture involved adapting clocking, input/output and FIFO ressources to Lattice specific macros/primitives. This involved effective use of LVDS, DLL, PLL and FIFO blocks from within the Lattice design software.The rest of the Core is written in architecture agnostic HDL code and cleanly implemented using the ispLEVER 7.0 software from Lattice.

The resulting image has successfully been loaded onto a SC/M 80 device. The "Lattice HTX Evaluation Board" equipped with an LFSCM3GA80 device in a fpBGA1152 has been used to prove functionality of the Core in a real system. The core was tested on an Iwill DK8-HTX based system.

The current release of the HT-Core includes the version for Lattice FPGAs as well as an example design. It is available for download from the CoEHT download page.


The HT-Core provides an efficient way to build user specific devices by mapping the core and device modules to a programmable logic device connected to the HyperTransport Link. It provides a comfortable and efficient way to evaluate user specific devices connected to the HyperTransport connector standardized under the name HTX-Connector.

The HT-Core is a non-coherent HyperTransport cave device. A cave is an endpoint device in a HyperTransport chain. The core is a low latency device with a queue based application interface. Three queues are provided in each direction:
  • posted queue
  • non-posted queue
  • response queue
The Lattice version currently supports an HT200 interface with 1.6 GByte/s of bidirectional bandwidth and a very low latency of 300 ns (PIO Read).

Scope of delivery

  • Verilog source code for mapping to Lattice SC series FPGAs. Verified on the Lattice-HTX-Evaluation-Board Computing evironment: Iwill DK8-HTX mainboard with LINUX-BIOS and HTX board. Also a HP DL145G3 machine has been used to test the device.
    A constraint file describing the pinout is included.

Board image


The HT-Core is available under an open source license to any interested party. The acquiring party will be obligated to secure a HyperTransport technology license if and by the time any of the party's products based on the HT-Core is openly promoted or sold. A royalty-free HyperTransport technology license can be acquired by simply becoming a member of the HyperTransport Technology Consortium. Complete information about HyperTransport Consortium membership classes, benefits, fees and application guidelines can be found here.

Last modified: 02.02.2018

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