External Memory Interfaces Stratix® 10 FPGA IP User Guide

ID 683741
Date 4/01/2024
Document Table of Contents

3.8.3. Stratix® 10 Ping Pong PHY Limitations

Ping Pong PHY supports up to two ranks per memory interface. In addition, the maximum data width is x72, which is half the maximum width of x144 for a single interface.

Ping Pong PHY uses all lanes of the address and command I/O bank as address and command. For information on pin allocations, refer to the pin-out file for your device, at Pin-Out Files for Intel FPGA Devices on www.altera.com.

An additional limitation is that I/O lanes may be left unused when you instantiate multiple pairs of Ping Pong PHY interfaces. The following diagram shows two pairs of x8 Pin Pong controllers (a total of 4 interfaces). Lanes highlighted in yellow are not driven by any memory interfaces (unused lanes and pins can still serve as general purpose I/Os). Even with some I/O lanes left unused, the Ping Pong PHY approach is still beneficial in terms of resource usage, compared to independent interfaces. Memory widths of 24 bits and 40 bits have a similar situation, while 16 bit, 32 bit, and 64 bit memory widths do not suffer this limitation.

Figure 22. Two Pairs of x8 Pin-Pong PHY Controllers