The refre rate change of MX287 LCDIF

[george]

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

[Yuri · Accepted solution]

  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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[george]

Thanks,

I investigate with a customer more based on your advice.

BR,

George