This part is a kind of semiconductor called ST7066U.

Function of this product has Dot Matrix LCD Controller/Driver.

Manufacturers : Sitronix

Image and pinout :

Some of the text within the PDF file :

ST Sitronix Features !" #" #" #" #" 5 x 8 and 5 x 11 dot matrix possible Low power operation support: -- 2.7 to 5.5V Wide range of LCD driver power -- 3.0 to 10V #" Correspond to high speed MPU bus interface -- 2 MHz (when VCC = 5V) #" 4-bit or 8-bit MPU interface enabled #" 80 x 8-bit display RAM (80 characters max.) #" 13,200-bit character generator ROM for a total of 240 character fonts(5 x 8 dot or 5 x 11 dot) #" 64 x 8-bit character generator RAM -- 8 character fonts (5 x 8 dot) -- 4 character fonts (5 x 11 dot) #" 16-common x 40-segment liquid crystal display driver ST7066U Dot Matrix LCD Controller/Driver #" Programmable duty cycles -- 1/8 for one line of 5 x 8 dots with cursor -- 1/11 for one line of 5 x 11 dots & cursor -- 1/16 for two lines of 5 x 8 dots & [ ... ]

ST7066U PDF Datasheet Download