regarding SDRAM

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regarding SDRAM

831 次查看
TEMCEFF
Contributor IV

1.sd ram data is corrupted when reading after some time, corrupted data  looks like data is shifted by 2 byte for 14 bytes. in LPC54608 iam using 4Mb*16 (AS4C4M16SA ) SD RAM.

2.if I started data feteching from a location that is multiples of 16 bytes data is not corrupted, if  I started data feteching location other than multiples of 16 bytes like multiples of 4 that is corrupted as mentioned above.

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618 次查看
TEMCEFF
Contributor IV

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 .

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jeremyzhou
NXP Employee
NXP Employee

Hi Muralidhar M,

Thank you for your interest in NXP Semiconductor products and
It seems a bit weird and I was wondering if you can share a compile-able demo which can replicate the phenomenon.
it's helpful to figure it out by me.

Have a great day,
TIC

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