thank sir.
the scenario is
when we write and read immediate it is working fine ,if we read after some time the the data bytes are shifting 2-4 bytes but occur randomly
example
the data written to SD RAM
0xA0000000 -> 0x00000000 0x44332211 0x88776655
0xA000000C->0x000000001 0x44332211 0x88776655
....
.....
data reading after some time
0xA0000000 -> 0x00000000 0x44332211 0x88778877
0xA000000C->0x000000001 0x44332211 0x88776655
the SD RAM we used is AS4C4M16SA-6TIN
the timming we have initialized
are
#define SDRAM_REFRESHPERIOD_NS (64 * 1000000 / 4096) /* 4096 rows/ 64ms */
#define SDRAM_TRP_NS (21u)
#define SDRAM_TRAS_NS (42u)
#define SDRAM_TSREX_NS (67u)
#define SDRAM_TAPR_NS (20u)
#define SDRAM_TWRDELT_NS (6u)
#define SDRAM_TRC_NS (60u)
#define SDRAM_RFC_NS (60u)
#define SDRAM_XSR_NS (67u)
#define SDRAM_RRD_NS (14u)
#define SDRAM_MRD_NCLK (2u)
#define SDRAM_RAS_NCLK (2u)
#define SDRAM_MODEREG_VALUE (0x33u)
#define SDRAM_DEV_MEMORYMAP (0x05u) /* 64Mbits (4M*16, 4banks, 12 rows, 8 columns)*/
we used SDK emc files .