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Application Note

Interfacing to a Graphics Module with a Toshiba
T6963C Controller

Page 1

Introduction:

Functional Description:

Schematic:

The Toshiba T6963C LCD controller is one of the most popular controllers for use in small graphics
displays. For this reason it is used in a number of LCD modules from 128x128 to 240x128 pixels.
This class of module is most commonly used to display a mixture of text and graphics in samall
devices and instruments. It is usually interfaced directly with an embedded 8-bit microprocessor.
This application note describes the use of this controller with a number of graphics modules.
The example used here is based on an 8-bit Intel I8051 microcontroller but applies to almost any
micro-controller.

The T6963C uses a simple 8-bit data bus to transfer all instructions and data to and from the
display. After power is applied a hardware reset is issued. The controller must then be initialized
with a series of commands to set up the various modes and options available to the user. Once
initialized the display is ready to accept the data to be displayed. This data can be in the form of
bit-mapped graphical data or text data in pseudo ASCII format. The internal character generator is
biased at -20h. which means the user must subtract 20h from the ASCII code before sending it to
the display.

In the bit-mapped mode each byte of data represents 8 pixels on the display. See Figure #1. Text
data can be written in pseudo ASCII format and will be displayed as a 5x7 dot character. The
graphical and text data are written to separate, user assigned, areas, or pages, in the display RAM
within the display module. The user can then choose one of three ways to mix the text and
graphics pages on the display or the text or graphics page can be displayed alone.

The 80C51 microprocessor is connected to the LCD controller chip via parallel I/O ports in this
example. It could also be connected to the processor's data bus and be mapped into the
processor's data memory area. See figure 2.

D0 D1 D2 D3 D4 D5 D6 D7 D0 D1

1 BYTE

ST

17 BYTE

TH

2

BYTE

ND

Figure #1 Memory map of a 128x128 display

Summary of Contents for T6963C

Page 1: ...o set up the various modes and options available to the user Once initialized the display is ready to accept the data to be displayed This data can be in the form of bit mapped graphical data or text data in pseudo ASCII format The internal character generator is biased at 20h which means the user must subtract 20h from the ASCII code before sending it to the display In the bit mapped mode each by...

Page 2: ...recede the command byte which is sent in the command mode The controller is initialized with the graphics page at 0000 077fh This is 1920 bytes which will accommodate a full screen of data No text is displayed in this example but the controller is initialized for text operation to illustrate the process The text page starts immediately following the graphics page at location 0780h The FS Font Sele...

Page 3: ...S NO DISPLAY BITMAP START INITIALIZE T6963C END MAIN PROGRAM LOOP STATUS STATUS CHECK SET C D TO 1 READ BYTE RDHIGH RD LOW STATUS OK YES NO RETURN GET BYTE FROM TABLE END BYTE YES NO CALL WRITED INC TABLE POINTER RETURN MSGD SEND A BLOCK OF DATA TO THE DISPLAY STATUS OK STATUS OK YES NO YES NO WRITEC WRITED WRITE A COMMAND BYTE WRITE A DATA BYTE RETURN DATA TO P1 WRHIGH WR LOW SET C D TO 1 SET C D...

Page 4: ...e parameters that accompany them along with a brief explanation of the function of each Where a parameter is different for a display that differs in resolution from the 240x64 example the alternate values are also listed TEXT AREA GRAPHIC AREA 41h 43h ADDRESSES AREFORMATTEDAS LSB MSB 240 240 160 128 8 8 8 8 240x128 240x64 240x128 240x64 LINE LENGTH IN CHARACTERS 20 14h FOR AN 8 BIT CHARACTER CELL ...

Page 5: ...0a1h msgc3 done ret msgc3 mov r1 a lcall writed send it Software inc dptr djnz r0 msgc2 clr a movc a a dptr get command mov r1 a lcall writec send command sjmp msgc next command MSGD sends the data pointed to by the DPTR to the graphics module msgd clr a movc a a dptr get byte cjne a 0a1h msgd1 done ret msgd1 mov r1 a lcall writed send data inc dptr sjmp msgd WRITEC sends the byte in R1 to a graph...

Page 6: ...graphic home address db 1eh 00 43h graphic area db 00 00 81h mode set db 00 00 24h address pointer set db 00 00 98h display mode set db 0a1h msgi2 db 00 00 0b0h auto mode db 0a1h 240x64 Bitmap graphic data Only the first 8 bytes are shown here The real graphic consists of 1920 bytes of binary data msg1 db 00h 00h 00h 00h 00h 00h 00h 00h db 0a1h end ...

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