IOD Features and User Modes

Each I/O (both GPIO and HSIO) has a digital block, called IOD, that interfaces with the FPGA fabric on one side and the IOA buffers on the other side (Figure 1). The IOD block includes several digital features, including I/O digital. The I/O digital allows for easy data transfer between the high-speed IOA buffers and the lower-speed FPGA core.

The IOD block can be configured for both input and output SDR and DDR modes. It also allows the gearing-up of the output data rate and gearing-down of the input data rate. These options are configured in Libero SoC and are used to build source synchronous I/O interfaces such as DDR and QDR memory controllers, common interfaces such as RGMII, MIPI D-PHY, 7:1 Video LVDS, and several other non-memory user interfaces.

This chapter provides information about the IOD block and the various I/O user modes, including various SDR, DDR, and digital modes.