17.5.8 Refresh Controls

Refresh can be issued using the auto-refresh feature in the UDDRC or using the direct software request of the refresh command. The RFSHCTL3.dis_auto_refresh register bit selects the refresh method (see Register Descriptions). When this bit is set to 1, UDDRC uses direct software request of refresh command. When it is set to 0, the internal auto-refresh feature is used.

The purpose of refresh control is to:

• Reduce the bandwidth impact of refresh cycles
• Increase the likelihood of refreshes being serviced during idle periods
• Provide fine-gain control of the trading-off the above benefits (to gather refreshes) versus the increased worst case latencies associated with gathering refreshes