36.5.3.1 All Banks Auto-Refresh

The All Banks Auto-refresh command performs a refresh operation on all banks. An auto-refresh command is used to refresh the external device. Refresh addresses are generated internally by the DDR-SDRAM device and incremented after each auto-refresh automatically. The MPDDRC generates these auto-refresh commands periodically. A timer is loaded in the MPDDRC_RTR with the value that indicates the number of clock cycles between refresh cycles (see MPDDRC Refresh Timer Register). When the MPDDRC initiates a refresh of the DDR-SDRAM device, internal memory accesses are not delayed. However, if the CPU tries to access the DDR-SDRAM device, the client indicates that the device is busy. A refresh request does not interrupt a burst transfer in progress. This feature is activated by setting Per-bank Refresh bit (REF_PB) to 0 in the MPDDRC_RTR (see MPDDRC Refresh Timer Register).