04-15-2019 04:46 AM
To perform Self refresh entry/exit as per the specification pg150, it is mentioned that mem_init_skip and app_restore_en signal has to be assert.
is it really required to assert the app_restore_en signal/ can we skip restore and still exit self refresh?
04-16-2019 11:26 PM
Thanks for the response,
I have some queries.
To perform save restore operation is it mandatory to do reset operation?
I am able to read the calibration data with XSDB ports when I put it in self refresh. is it possible to restore the calibration data with XSDB ports without reset?
If reset is mandatory, we will lose the data which we already stored in the memory. is there any other way to retain the data with self refresh entry and exit?
It is better if you share KT on how to access Mode Register.
04-17-2019 01:46 AM
Are you talking about the reset of DDR4 IP? When the DDR4 has been in self-fresh mode, the data will be safe.
As per the DRAM protocol, the memory interface signals cke and reset_n must be maintained at 0 and 1 values respectively to keep the DRAM in self-refresh mode.
04-17-2019 02:03 AM
Please find the attachment below. there he mentioned that mem_init_skip and app_restore_en has to be assert within 50 interconnect cycles after the user interface reset is deasserted in the self refresh exit cycle.