Device Family: Stratix® IV E, Stratix® IV GX

Type: Answers

Area: EMIF, Intellectual Property

IP Product: DDR3 SDRAM Controller MegaCore supporting UniPHY

Why do I get Burst Chop when accesing DDR3 SDRAM using Altmemphy based DDR3 SDRAM Controller?


You will see burst chop when accessing DDR3 SDRAM using Altmemphy based Controller if local_size is set to 1. When local_size=1 ,you will not get Burst Length (BL) of 8 for consecutive addresses, but only Burst chop. If you need BL of 8 to improve the efficiency, you need to enable burst merge option.


Burst merge was introduced as option in controller setting tab of Altmemphy based DDR3 SDRAM Controller in the Quartus® II design software 10.1.


Burst Merge option will be added in UniPHY based DDR3 SDRAM Controller in the future version of the IP.