External Memory Interface Handbook Volume 3: Reference Material: For UniPHY-based Device Families

ID 683841
Date 3/06/2023
Public
Document Table of Contents

5.3.3. Quasi-1T and Quasi-2T

One controller clock cycle equals two memory clock cycles in a half-rate interface, and to four memory clock cycles in a quarter-rate interface. To fully utilize the command bandwidth, the controller can operate in Quasi-1T half-rate and Quasi-2T quarter-rate modes.

In Quasi-1T and Quasi-2T modes, the controller issues two commands on every controller clock cycle. The controller is constrained to issue a row command on the first clock phase and a column command on the second clock phase, or vice versa. Row commands include activate and precharge commands; column commands include read and write commands.

The controller operates in Quasi-1T in half-rate mode, and in Quasi-2T in quarter-rate mode; this operation is transparent and has no user settings.