Interface circuit of dot matrix LCD display

Shown is the interface circuit using MCS-51 series microcontroller 8051 . The chip SED13 35 is a dot matrix LCD display
controller, which can control up to 640×256 dot matrix LCD displays for graphics and character display, and can address a 64KB display buffer
.
    In the figure - the functions of each port of the LCD display are as follows; D3~DO are display data ports; DP is the non-display power off control signal} YD is the Y (column) driving data output valid signal; FR is the frame control signal; XECL is X ( row) drive data output valid signal; XSCL data port data latch signal.   The PO port of the 8051 microcontroller is used as the data port . When programming in assembly language, the instruction MOVXA is used. @Ri (that is, indirect access to external RAM) is used to exchange data with SED1335. When programming in C language, SED1335 is accessed in pointer mode.