1. MAX® 10 External Memory Interface Overview
                    
                    
                
                    
                        2. MAX® 10 External Memory Interface Architecture and Features
                    
                    
                
                    
                        3. MAX® 10 External Memory Interface Design Considerations
                    
                    
                
                    
                        4. MAX® 10 External Memory Interface Implementation Guides
                    
                    
                
                    
                        5. UniPHY IP References for MAX® 10 Devices
                    
                    
                
                    
                    
                        6. MAX® 10 External Memory Interface User Guide Archives
                    
                
                    
                    
                        7. Document Revision History for the MAX® 10 External Memory Interface User Guide
                    
                
            
        
                        
                        
                            
                            
                                2.1. MAX® 10 I/O Banks for External Memory Interface
                            
                        
                            
                            
                                2.2. MAX® 10 DQ/DQS Groups
                            
                        
                            
                            
                                2.3. MAX® 10 External Memory Interfaces Maximum Width
                            
                        
                            
                            
                                2.4. MAX® 10 Memory Controller
                            
                        
                            
                                2.5. MAX® 10 External Memory Read Datapath
                            
                            
                        
                            
                                2.6. MAX® 10 External Memory Write Datapath
                            
                            
                        
                            
                            
                                2.7. MAX® 10 Address/Command Path
                            
                        
                            
                            
                                2.8. MAX® 10 PHY Clock (PHYCLK) Network
                            
                        
                            
                            
                                2.9. Phase Detector for VT Tracking
                            
                        
                            
                            
                                2.10. On-Chip Termination
                            
                        
                            
                            
                                2.11. Phase-Locked Loop
                            
                        
                            
                            
                                2.12. MAX® 10 Low Power Feature
                            
                        
                    
                3.1.2. DDR2/DDR3 Recommended Termination Schemes for MAX® 10 Devices
If you are creating interfaces with multiple DDR2 or DDR3 components where the address, command, and memory clock pins are connected to more than one load, follow these steps:
- Simulate the system to get the new slew rate for the DQ/DQS, DM, address and command, and clock signals.
 - Use the derated tIS and tIH specifications from the DDR2 or DDR3 datasheet based on the simulation results.
 - If timing deration causes your interface to fail timing requirements, consider duplication of these signals to lower their loading, and hence improve timing.
 
    Note: Class I and Class II termination schemes in the following tables refer to drive strength and not physical termination. 
   
 
   | Signal Type | SSTL 18 I/O Standard | FPGA–End Discrete Termination | Memory–End Termination 1 | Memory I/O Standard | 
|---|---|---|---|---|
| DQ/DQS | Class I Rs = 50 Ω | 50 Ω parallel to VTT discrete | ODT75 4 | HALF 5 | 
| DM | Class I Rs = 50 Ω | — | ODT754 | HALF5 | 
| Address and command | Class I with maximum drive strength | — | 56 Ω parallel to VTT discrete | — | 
| Clock | Differential Class I Rs = 50 Ω | — | — | 
| I/O Standard | RS OCT | On Board Termination | |
|---|---|---|---|
| FPGA–End | Memory-End | ||
| SSTL 15 Class 1 | 50 Ω without calibration | 80 Ω resistor | 40 Ω resistor | 
| Memory Interface Standard | I/O Standard | RS OCT | RUP, RDN (Ω) | 
|---|---|---|---|
| DDR3 | SSTL-15 | 25 | 25 | 
| 34 | 34 | ||
| 40 | 40 | ||
| 50 | 50 | ||
| DDR3L | SSTL-135 | 34 | 34 | 
| 40 | 40 | ||
| DDR2 | SSTL-18 | 25 | 25 | 
| 50 | 50 | 
  4 ODT75 vs. ODT50 on the memory has the effect of opening the eye more, with a limited increase in overshoot/undershoot. 
 
 
 
  5 HALF is reduced drive strength. 
 
 
 
  6 x1 is a single-device load. 
 
 
 
  7 x2 is a two-device load.