The EMIF does not support a software reset.
The EMIF supports a global warm reset mode, during which the EMIF keeps the SDRAM content. Upon a request from the PRCM module indicating a need to enter global warm reset mode, the EMIF does the following:
- During leveling operation, EMIF will immediately exit this mode and automatically perform a write to the MR1 register of DDR3 memory to disable the leveling at the memory side too.
- EMIF completes the ongoing access, and then puts the SDRAM in self-refresh mode. If the EMIF_SDRAM_REFRESH_CONTROL[31] INITREF_DIS field is set to 1, the EMIF does not put SDRAM in self-refresh mode.
- EMIF clears all its FIFO contents.
- EMIF does not wait for all interrupts to be serviced.
To exit the global warm reset:
- If the EMIF was in Self Refresh state, it will exit Self Refresh state.
- If leveling was enabled at the time of a global warm reset, a PHY reset must occur to bring the PHY back into a known state, as it may have been left in a leveling state upon warm reset assertion. To guarantee that the SDRAM memory clocks are off when issuing PHY reset, software can use the EMIF_POWER_MANAGEMENT_CONTROL register to enter self refresh before asserting the PHY reset.