The refre rate change of MX287 LCDIF

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The refre rate change of MX287 LCDIF

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george
Senior Contributor II

Dear All,

Our customer is doing the product design using i.MX287 currently.

Their product is used with 3.5 inch LCD (320x240).

They are going to set the LCD Reflesh-rate to 90Hz.

However, they see 56Hz Reflesh-rate.

Setting the following in DOTCLK mode

  • HW_LCDIF_VDCTRL0.HALF_LINE = 0
  • HW_LCDIF_VDCTRL0.VSYNC_PERIOD_UNIT = 1

Is Reflesh-rate correct at the following understanding?

  • Reflesh-rate = HW_LCDIF_VDCTRL1.VSYNC_PERIOD x HW_LCDIF_VDCTRL2.HSYNC_PERIOD x Period of CLK_DIS_LCDIFn

Is there any point that something must take care about others?

Best Regards,

George

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Yuri
NXP Employee
NXP Employee

  Looking over Figure 33-13 (LCD Interface Signals in DOTCLK Mode)
of the i.MX28 Reference Manual – refresh rate formula in Your case
is correct. Also,  please refer to section 33.2.8.1 (Code Example) about
LCD initialization, where 320 x 240 resolution is configured via :
VSYNC_PERIOD = 280 and HSYNC_PERIOD = 360 ; back and front porch
periods are taken into account.


Have a great day,
Yuri

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517 Views
Yuri
NXP Employee
NXP Employee

  Looking over Figure 33-13 (LCD Interface Signals in DOTCLK Mode)
of the i.MX28 Reference Manual – refresh rate formula in Your case
is correct. Also,  please refer to section 33.2.8.1 (Code Example) about
LCD initialization, where 320 x 240 resolution is configured via :
VSYNC_PERIOD = 280 and HSYNC_PERIOD = 360 ; back and front porch
periods are taken into account.


Have a great day,
Yuri

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

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george
Senior Contributor II

Thanks,

I investigate with a customer more based on your advice.

BR,

George

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