topic Re: Changing DDR memory map in SabreSD in i.MX Processors

Changing DDR memory map in SabreSD

vijaikumar — Wed, 10 Jun 2015 09:38:10 GMT

Hi,

We are developing a custom board based on SABRESD reference platform. We use a lpddr instead of ddr3. Our DDR memory map is configured as single channel, we would like to change it to fixed 2x32 map. Is there any means we can do this in software?

Re: Changing DDR memory map in SabreSD

igorpadykov — Wed, 10 Jun 2015 14:26:59 GMT

Hi Vijai

i.MX6 uboot DDR configuration contained in:

for LTIB BSP:

<u-boot directory>/board/freescale/mx6q_sabresd/flash_header.S

for Yocto BSP:

<u-boot directory>/board/freescale/imx/ddr/mx6q_4x_mt41j128.cfg

also configuration is defined in uboot/include/configs/*board*.h files, like

#define CONFIG_NR_DRAM_BANKS

#define PHYS_SDRAM_1

#define PHYS_SDRAM_1_SIZE

then uboot passes ddr configuration to kernel.

Best regards

igor

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Re: Changing DDR memory map in SabreSD

vijaikumar — Wed, 10 Jun 2015 14:47:37 GMT

Hi igorpadykov

Actually in our hardware the fusemap is set as single channel. I want to override the fusemap provided in hardware. I heard that we can burn the fuses. But I donot know the procedure for the same. It would be great if you could guide me on this.

Re: Changing DDR memory map in SabreSD

igorpadykov — Wed, 10 Jun 2015 14:58:42 GMT

MMDCx_MDMISC , LPDDR2_2CH bit sets 2-channels mode

~igor

Re: Changing DDR memory map in SabreSD

vijaikumar — Thu, 11 Jun 2015 10:31:10 GMT

Hi igorpadykov

Those DCD values will be generated by the LPDDR2 excel sheet provided by freescale. I checked my DCD table, it is configured as dual channel. However in hardware fusemap it is fixed as Single channel. I would like to know the procedure to override that.

Re: Changing DDR memory map in SabreSD

igorpadykov — Thu, 11 Jun 2015 11:35:30 GMT

Hi Vijai

one can blow this fuse using:

Q&A: How to program i.MX6 eFUSE?

https://community.freescale.com/docs/DOC-95458

Best regards

igor