External Memory Interfaces Intel® Agilex™ FPGA IP User Guide
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4.2.3. AFI Write Data Signals
|   Signal Name  |  
         Direction  |  
         Width  |  
         Description  |  
      
|---|---|---|---|
|   afi_dqs_burst  |  
         Input  |  
         AFI_RATE_RATIO  |  
         Controls the enable on the strobe (DQS) pins for memory devices. When this signal is asserted, mem_dqs and mem_dqsn are driven. This signal must be asserted before afi_wdata_valid to implement the write preamble, and must be driven for the correct duration to generate a correctly timed mem_dqs signal.  |  
      
|   afi_wdata_valid  |  
         Input  |  
         AFI_RATE_RATIO  |  
         Write data valid signal. This signal controls the output enable on the data and data mask pins.  |  
      
|   afi_wdata  |  
         Input  |  
         AFI_DQ_WIDTH  |  
         Write data signal to send to the memory device at double-data rate. This signal controls the PHY’s mem_dq output.  |  
      
|   afi_dm  |  
         Input  |  
         AFI_DM_WIDTH  |  
         Data mask. Also directly controls the PHY's mem_dbi signal for DDR4. The mem_dm and mem_dbi features share the same port on the memory device.  |