External Memory Interfaces Intel® Agilex™ FPGA IP User Guide

ID 683216
Date 1/31/2022

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3.1.2. Intel® Agilex™ EMIF Architecture: I/O SSM

Each I/O row includes one I/O subsystem manager (I/O SSM), which contains a hardened Nios® II processor with dedicated memory. The I/O SSM is responsible for calibration of all the EMIFs in the I/O row. There is one I/O SSM in the top row and bottom row. It's location is fixed in one of the I/O banks along each edge and depends on the base die.

The I/O SSM includes dedicated memory which stores both the calibration algorithm and calibration run-time data. The hardened Nios® II processor and the dedicated memory can be used only by an external memory interface, and cannot be employed for any other use. The I/O SSM can interface with soft logic, such as the debug toolkit, via an Avalon® memory-mapped interface bus.

The I/O SSM is clocked by the on-chip configuration network, and therefore does not consume a PLL.

Each EMIF instance must be connected to the I/O SSM through the External Memory Interfaces Calibration IP. The Calibration IP exposes a calibration bus master port, which must be connected to the slave calibration bus port on every EMIF instance.

Only one calibration IP is allowed for each I/O row. All the EMIFs in the same I/O row must be connected to the same calibration I/P. You can specify the number of EMIF interfaces to be connected to the calibration IP when parameterizing the IP. Connect the emif_calbus and emif_calbus_clk on the calibration IP to the emif_calbus and emif_calbus_clk, respectively, on the EMIF IP core.

Figure 3. Connectivity Between Calibration IP and Single EMIF Interface
Figure 4. Connectivity Between Calibration IP and Multiple EMIF Interfaces on the Same I/O Row