HOW USE CUBEMX HAL_LCD_WRITE?

It is the starter that started now.

We are currently using the STM32L152C-DISCOVERY board.

I have used HAL_LCD_WRITE as shown below, but nothing is displayed on the LCD.

HAL_LCD_WRITE (& hlcd, LCD_RAM_REGISTER0, 0x0000, 0xffff);

or

HAL_LCD_WRITE (& hlcd, LCD_RAM_REGISTER0, ~ (0x0000), 0xffff);

HAL_LCD_UpdateDisplayRequest (& hlcd);

How do I use this command?

And what does RAMRegisterMask mean?