Wong Mun Lai

writing to SDRAM problem

Discussion created by Wong Mun Lai on Nov 14, 2006
Latest reply on May 6, 2009 by Edison Tran
Hi,
we have a board with MCF5235 coldfire connected to a
128Mbit Sdram (ELPIDA EDS1216AGTA 8M words x 16 bit) chip. It is connected with the
following configurations:
16-bit Port,9-Column Address
MCF5235 Pin - A16 A15 A14 A13 A12 A11 A10 A9  A18 A19 A20 A21  A22  A23
SDRAM Pin   - A0    A1   A2   A3   A4   A5   A6   A7  A8   A9   A10 A11  BA0  BA1
where BA0,BA1 are the Bank Select Addresses
 
We currently face a problem when reading and writing to SDRAM using the  Pemicro ICDCFZ_PRO BDM debugger.
 
We have configured the SDRAM memory space to start from 0x10000000 to 0x10FFFFFF.
We have no problem reading and writing to the first half of that memory space (0x10000000 to 0x107fffff).
But when we try to write to to the 2nd half of that memory space(0x10800000 to 0x10ffffff), this is what happened:
 
when we write a byte to 0x10800000, another location 0x10800008 gets written with the same value.
 when we write a byte to 0x10800001, another location 0x10800009 gets written with the same value.
 when we write a byte to 0x10800002, another location 0x1080000A gets written with the same value.
 when we write a byte to 0x10800003, another location 0x1080000B gets written with the same value.
 when we write a byte to 0x10800004, another location 0x1080000C gets written with the same value.
 when we write a byte to 0x10800005, another location 0x1080000D gets written with the same value.
 when we write a byte to 0x10800006, another location 0x1080000E gets written with the same value.
 when we write a byte to 0x10800007, another location 0x1080000F gets written with the same value.
 when we write a byte to 0x10800008, another location 0x10800000 gets written with the same value.
 when we write a byte to 0x10800009, another location 0x10800001 gets written with the same value.
when we write a byte to 0x1080000A, another location 0x10800002 gets written with the same value.
when we write a byte to 0x1080000B, another location 0x10800003 gets written with the same value.
when we write a byte to 0x1080000C, another location 0x10800004 gets written with the same value.
when we write a byte to 0x1080000D, another location 0x10800005 gets written with the same value.
when we write a byte to 0x1080000E, another location 0x10800006 gets written with the same value.
when we write a byte to 0x1080000F, another location 0x10800007 gets written with the same value.
when we write a byte to 0x10800010, another location 0x10800018 gets written with the same value.
....... and so on.......
 
This problem seems to appear only on the 2nd half of the SDRAM memory space. We are puzzled as to what could have caused it to behave this way. Hope someone could give us some answers.
 
Thanks in advance!
Mun Lai
 

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