5.1.2. Memory device initialization

Memory initialization involves writing to the direct_cmd Register. See Direct Command Register. To initialize the mode registers in a memory device you must perform multiple writes to the direct_cmd Register, so that the controller generates the necessary sequence of commands that your specified memory requires.

A typical memory initialization sequence for each memory device is:

  1. Program the direct_cmd Register so that the DMC issues a PRECHARGEALL command.

  2. Set Extended Mode Register.

  3. Set Mode Register.

  4. Program the direct_cmd Register so that the DMC issues a PRECHARGEALL command.

  5. Program the direct_cmd Register so that the DMC issues two AUTO REFRESH commands.

LPDDR device initialization shows a memory initialization example.

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