About clock tree in i.MX6DQ.

[keitanagashima]

Dear All,

I referred to ”Figure 18-2. Clock Tree - Part 1” and ”Figure 18-3. Clock Tree - Part 2” in IMX6DQRM（Rev.3).

But, the some difference was seen between jb4.2.2's setting and Reference Manual (RM).

                                                    [RM]　　　[JB4.2.2]

GPU2D_CORE_CLK_ROOT　　 352MHz   480MHz

GPU3D_CORE_CLK_ROOT     594MHz   528MHz

GPU3D_SHADER_CLK_ROOT 720MHz   594MHz

ENFC_CLK_ROOT               198MHz   19.8MHz

PERCLK_CLK_ROOT            16.5MHz   22MHz

[Q1]

Why are there differences in the clock?

[Q2]

Is the setting of JB4.2.2 right?

Best Regards,

Keita

[Bio_TICFSL · Accepted solution]

Hi Keita,

For MX6DQ, current 2d clock is 480MHz. Current 3d core clock is 528MHz, current 3d shader clock is 594MHz. We don't recommend changing the gpu clock. If any case you want to change it, you can try the clock divider for such root clock. And the clock divider should be done before gpu driver loading. Settings on jb are ok.

[keitanagashima]

Dear Alfred,

Hello. Thank you for your reply.

> We don't recommend changing the gpu clock.

OK. I got it.

Best Regards,

Keita