Initcode is used to set up CGU, bit rates, wait states, and the external memory controllers in booting.
As ADSP-21565 doesn't support a DDR3 controller, please make a copy of the below project and define CONFIG_DMC0 as DMC_NONE in the "config.h" file to disable the initialization code for DDR in init code.
<Installation path>:\Analog Devices\CrossCore Embedded Studio 2.11.1\SHARC\ldr\init_code\2156x_Init\21569_init
Once changes are made build and use the updated init code.