8168 u-boot DDR3 clock speeds

Richard lane

Hi all,

We are using u-boot from the EZ-SDK branch of 8168 software. U-boot has 4 choices for DDR3 speeds, but the .gel file that we use for DDR3 leveling has many more clock choices for clock speeds between those in u-boot. Is there some fundamental limit in the 8168 DDR hardware that limits us to the smaller set of u-boot clocks, or can we use any of the clocks supported in the leveling gel file?

Has anybody tried this?

Thanks,

Rich

over 10 years ago

Pavel Botev over 10 years ago

TI__Guru**** 170625 points

Hi Richard,

DDR3 max speed depends on the specific DM816x device speed range. See latest DM816x datasheet (March-2015):
Table 8-13. PLL Clock Frequencies
Table 9-13. Switching Characteristics Over Recommended Operating Conditions for DDR3 Memory Controller - the max is 800MHz (1600 rate).

Regards,
Pavel

Pavel Botev over 10 years ago in reply to Pavel Botev

TI__Guru**** 170625 points

See also latest DM816x silicon errata (March 2015):

Advisory 2.1.108 PLL: Maximum Operating Frequencies Reduced for Each Speed Grade Device

BR
Pavel

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8168 u-boot DDR3 clock speeds