I am writing driver code for grove lcd so i need datasheet.
As far as I know this is just a HD44780 with an I2C I/O expander chip and a RGB LED controller… most of what you want should be found in the HD44780 datasheet and the driver from Seeed should be able to fill in the gaps: https://github.com/Seeed-Studio/Grove_LCD_RGB_Backlight
I’m afraid if you need to know more than this you’ll have to contact Seeed; it’s their product!
PS I strongly suggest taking anti-static precautions when handling this device. I’ve managed to static zap both of mine!