Synthesizable DDR-SDRAM PHY is a third-generation, DFI-compliant PHY IP block which is a complete process-independent solution ready to be integrated into SoCs and ASICs which interface with DDR-SDRAM memories. Each configurable PHY is delivered to match the unique requirements of the customer's DDR application. Using the PHY reduces risk and time-to-market for deploying memory interfaces in silicon. Cadence Design IP: DDR DLL PHY Technical Brief » Cadence Design IP: DDR Phase PHY Technical Brief » Cadence Design IP: DDR (Hard) DLL PHY For TSMC 40LP, 40G, and 28HPM processes »
The RTL-based design provides flexibility to easily fit into your floorplan and allows you complete control of the padring. Other strengths, as compared to hard macros, include well known DFT and DFM techniques since the PHY is based on cells from your standard cell library. Because the PHY is built from standard cells, designers can use a normal, digital, automatic place-and-route flow.
Using the DDR PHY Interface (DFI) ensures re-usability since the same PHY may be used with different memory controllers. With DFI, all handling of multiple timing domains, data capture, and data re-synchronization happens within the PHY leaving memory controller logic as purely digital, with simple timing constraints.
The PHY data slice integrates several components including the DDR I/O pads and optionally, an analog DLL, to handle 8 bits of data. When using an analog DLL, the majority of the slice's area is dominated by the DLL. Multiple DDR PHY data slices are instantiated along with the address and control logic to assemble the PHY. Placement is flexible so that a PHY with arbitrary aspect ratio can be constructed.