diff options
| author | Caesar Wang <wxt@rock-chips.com> | 2017-05-04 09:24:23 +0800 |
|---|---|---|
| committer | Julius Werner <jwerner@chromium.org> | 2017-05-11 04:55:02 +0200 |
| commit | e085a8a359a82bce204fe15325e1aead53aa3edd (patch) | |
| tree | 875d49f8dc195231e946f2cdd3bad68b480cd427 /src/soc/rockchip/rk3399/Kconfig | |
| parent | 65d15c0f11f2cb986c080c521bec67121723e853 (diff) | |
rockchip/rk3399: enable DPLL SSC for DDR EMI test on bob
Spread Spectrum Modulator (SSMOD) is a fully-digital circuit used to
modulate the frequency of the Silicon Creations’ Fractional PLL in order
to reduce EMI.
We need to turn the DPLL spread spectrum feature on to
reduce the EMI noise for DDR on bob.
Change-Id: I75461d4235bcf55324e6664a1220754e770b4786
Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Reviewed-on: https://review.coreboot.org/19557
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Diffstat (limited to 'src/soc/rockchip/rk3399/Kconfig')
| -rw-r--r-- | src/soc/rockchip/rk3399/Kconfig | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/soc/rockchip/rk3399/Kconfig b/src/soc/rockchip/rk3399/Kconfig index 65b31d523e..ff857c022c 100644 --- a/src/soc/rockchip/rk3399/Kconfig +++ b/src/soc/rockchip/rk3399/Kconfig @@ -24,4 +24,12 @@ config PMIC_BUS int default -1 +config RK3399_SPREAD_SPECTRUM_DDR + bool "Spread-spectrum DDR clock" + default n + help + Select Spread Spectrum Modulator (SSMOD) is a fully-digital circuit + used to modulate the frequency of the Silicon Creations’ Fractional + PLL in order to reduce EMI. + endif |