topic ddr clock frequency in i.MX Processors

ddr clock frequency

jdt — Fri, 21 Feb 2020 12:01:15 GMT

Hi,

We have a custom board based on imx7d with DDR2 RAM. The current DDR2 RAM is running at 533 MHz, but the DDR2 only support up to 400MHz.

In the bootloader we select clock source use DRAM_ALT_CLK_ROOT and SYS_PLL_PFD0 and hereby the DDR phy clock is running at 392Mhz.

When the Linux kernel boot, the DRAM clock dead after statement clks[IMX7D_DRAM_ALT_ROOT_CLK] = imx_clk_gate4("dram_alt_root_clk", "dram_alt_post_div", base + 0x4130, 0) in source file clk-imx7d.c.

Looking forward for inputs.

Thanks,

Jakob

Re: ddr clock frequency

Yuri — Sat, 22 Feb 2020 09:13:14 GMT

Hello,

i.MX7D supports DDR3 / DDR3L / LPDDR2 / LPDDR3 memory devices.

DDR2 is not supported.

Regards,

Yuri.

Re: ddr clock frequency

jdt — Mon, 24 Feb 2020 07:39:43 GMT

Hi,

It is a LPDDR2 SDRAM from Micron.

Regards,

Jakob

Re: ddr clock frequency

Yuri — Wed, 11 Mar 2020 09:16:40 GMT

Hello,

What NXP (Linux) BSP is used in the case?

Regards,

Yuri.

Re: ddr clock frequency

Jakobthomsen — Thu, 12 Mar 2020 08:55:25 GMT

Hi,

It has been decided to use a another memory device. Thank you for replying.

Regards,

Jakob