PCI Express to Wishbone Bridge

Communication

Introduction

We were asked to migrate the SPI slave interface of an existing FPGA design to PCIe® interface providing massively more bandwidth, while maintaining the FPGA-internal Wishbone communication infrastructure and as much as possible of the embedded software controlling the SPI master.

Customer Challenge

The main challenges for our customer were increasing performance requirements for the FPGA/CPU-interface and the lack of FPGA design expertise in their own development team. Also, the migration from SPI to PCIe should be transparent to the customer’s already existing host software application.

The Solution

We replaced the SPI slave interface with a multifunction PCIe endpoint with attached Wishbone masters and mapped the new FPGA design to an Intel® Cyclone® V GX device. In addition to the Wishbone masters, a sophisticated DMA engine, which takes care of the higher-bandwidth data transfers, was developed. On the embedded software side, the low-level SPI driver was replaced by a tailored PCIe driver, providing the same API and emulating the same behavior.

The Result

«Enclustra reworked and extended our existing FPGA design, which is a central part of a series of specialized measurement devices. Enclustra represents the FPGA expertise in our development team, and we look forward to working with them to further extend the functionality of our product line.» Florian Leitner, Leiter Sondermaschinenbau Elektrotechnik, Schaeffler Technologies AG & Co. KG .

Keywords

Intel® Cyclone® V | PCI Express | Wishbone | DMA | VHDL | FPGA System Design | FPGA DHL | Embedded Software