User`s manual
RTD Embedded Technologies, Inc. | www.rtd.com   27  FPGA35S6 User’s Manual 
6.1.19  R_DDR_STATUS (READ) 
This is a status register for the DDR2 memory interface. 
B0: Read error 
B1: Read overflow 
B2: Read empty 
B3: Read full 
B4: Write error 
B5: Write underrun 
B6: Write empty 
B7: Write full 
B[14:8]: Read count 
B[22:16]: Write count 
B[24]: Command full 
B[25]: Command empty 
B[31]: Calibration done 










