@mitu
It worked! thanks a lot.
I'm using "Version: 1.4.1" for retroarch.
I just wrote a script in python to send UDP packets with this command
"READ_CORE_RAM <address> <len>"
Then I received related bytes.

@Solid-One Thank you for your reply. It is interesting that you had no issue with the same game using an earlier version of RetroPie on a Raspberry Pi 2. I have submitted a report at https://github.com/libretro/pcsx_rearmed/issues/350 as you suggested.