DDR SDRAM Initialization.
sivakumar
sivakumar.subramani at wipro.com
Mon Jan 13 08:45:00 CET 2003
Thanks for the information.
I have gone through the code and have following query.
Following is the one of the step in Initialization of DDR SDRAM.
-Next a MODE REGISTER SET command should be issued for the Extended
Mode Register to enable the DLL,
/* 5. Issue EMRS to enable DLL */
SET_RAM_COMMAND(RAM_COMMAND_EMRS)
movl (0x0000<<MD_SHIFT), %eax
DO_DELAY
First we are setting the Mode select bit of DRAM controller Mode
Register to Extended Mode Register Set Enable.
>From DDR spec, it is given that zero bit of EMRS will enable the DLL.
Here I want to know how by moving the (0x0000 << MD_SHIFT) to eax
register, we are writting to Extended mode register.
Can any one explain this?
Thanks,
Siva
On Mon, 2003-01-13 at 05:07, Ronald G. Minnich wrote:
> On 12 Jan 2003, sivakumar wrote:
>
> > I want to support DDR SDRAM in linuxbios. When was browsing the code, I
> > found only the SDRAM support. Also I found from the specification that
> > Initialization sequence of DDR SDRAM and SDRAM are different.
>
> DDR is in there, see the 7500 port.
>
> kron
--
sivakumar <sivakumar.subramani at wipro.com>
wipro
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