This section covers Graphical Liquid Crystal Display (GLCD) devices that use the Toshiba T6963 graphics controller. The
T6963 is a monochrome device that typically is blue or white. The GLCD can be provided in a number of pixels sizes - 240
* 64 or 240 * 128.
The Toshiba T6963 is a very popular LCD controller for use in small graphics modules. It is capable of controlling displays
with a resolution up to 240x128. Because of its low power and
small outline it is most suitable for mobile applications such as PDAs, MP3 players or mobile measurement equipment.
A number of GLCD modules have this controller built-in these include the SP12N002 & SP14N001. Although this controller is
small, it has the capability of displaying
and merging text and graphics and it manages all the interfacing signals to the displays Row and Column drivers. The GCBASIC
library supports the complex capabilities of the T6963.
The T6963 is an LCD is driven by on-board 5V parallel interface chipset T6963. For the specific operating voltage always
verify the operating voltages in the device specific datasheet.
The GCBASIC connectivity option is the 8-bit mode - where 8 connections (for the data) are required between the microcontroller
and the GLCD to control the data bus.
To use the T6963 driver simply include the following in your user code. This will initialise the driver.
#chip 16f1939,32 #option explicit '*********************************************************************************************** 'Specify this GLCD - a 240 x 64 pixels display #include <glcd.h> #define GLCD_TYPE GLCD_TYPE_T6963_64 '*********************************************************************************************** 'define the connectivity - the 8bit port #define GLCD_DATA_PORT PORTD 'Library support contigous 8-bit port ' or ' #define GLCD_DB0 PORTD.0 'chip specific configuration where the ibrary supports 8-bit port defined via 8 constants ' #define GLCD_DB1 PORTD.1 'chip specific configuration ' #define GLCD_DB2 PORTD.2 'chip specific configuration ' #define GLCD_DB3 PORTD.3 'chip specific configuration ' #define GLCD_DB4 PORTD.4 'chip specific configuration ' #define GLCD_DB5 PORTD.5 'chip specific configuration ' #define GLCD_DB6 PORTD.6 'chip specific configuration ' #define GLCD_DB7 PORTD.7 'chip specific configuration #define GLCD_CS PORTa.7 'Chip Enable (Active Low) #define GLCD_CD PORTa.0 'Command or Data conrol line port #define GLCD_RD PORTA.1 'Read control line port #define GLCD_WR PORTA.2 'Write control line port #define GLCD_RESET PORTA.3 'Reset port #define GLCD_FS PORTA.5 'FS port #define GLCD_FS_SELECT 1 'FS1 Font Select port. 6x8 font: FS1=“High”=1 8x8 font FS1=“Low”=0 for GLCD_FS_SELECT '*********************************************************************************************** '* '* Note : The T6963 controller's RAM address space from $0000 - $7FFF, total 32kbyte RAM, or it could be 64kbyte RAM best check!! '* '*********************************************************************************************** #define TEXT_HOME_ADDR 0x0000 'This is specific to the GLCD display #define GRH_HOME_ADDR 0x3FFF 'This is specific to the GLCD display #define CG_HOME_ADDR 0x77FF 'This is specific to the GLCD display #define COLUMN 40 'Set column number to be 40 , 32, 30 etc. This is specific to the GLCD display #define MAX_ROW_PIXEL 64 'MAX_ROW_PIXEL the physical matrix length (y direction) This is specific to the GLCD display #define MAX_COL_PIXEL 240 'MAX_COL_PIXEL the physical matrix width (x direction) This is specific to the GLCD display '*********************************************************************************************** '* End of configuration '***********************************************************************************************
The GCBASIC constants for the interface to the controller are shown in the table below.
Constants | Controls | Options |
---|---|---|
|
|
Required |
|
A full 8-bit port. 8 contigous input/outputs. |
or use GLCD_DB0..GLCD_DB7 |
|
A 8-bit port using 8 input/outputs. |
or use GLCD_DATA_PORT |
|
Specifies the output pin that is connected to Chip Select on the GLCD. |
Required |
|
Specifies the output pin that is connected to Command/Data on the GLCD. |
Required |
|
Specifies the output pin that is connected to Read on the GLCD. |
Required |
|
Specifies the output pin that is connected to Write on the GLCD. |
Required |
|
Specifies the output pin that is connected to Reset on the GLCD. |
Required |
|
Specifies the output pin that is connected to FS on the GLCD. The FS specifies the font size. Please set to 6 setting GLCD_FS_SELECT = 1 |
Required |
|
Specifies the output pin that is connected to FS on the GLCD. The FS specifies the font size. Please set to 6 setting GLCD_FS_SELECT = 1 |
Required. Can be 1 or 0. Default setting is 1. |
The T6963 differs from most other GLCD controllers in its use of the display RAM. Where a fixed area of memory is normally allocated for text, graphics and the external character generator, but with the T6963 the size for each area MUST be set by software commands. This means that the area for text, graphics and external character generator can be freely allocated within the external memory, up to 64 kByte. Check the specific device for the amount of memory available. This can range from 4 kbyte to 64 kbyte.
For more information on memory management refer the device specific datasheet.
The GCBASIC constants control the memory configuration of the T6963 controller.
Constants | Value | Comments |
---|---|---|
|
0x0000 |
This is specific to the GLCD display |
|
0x3FFF |
This is specific to the GLCD display |
|
0x77FF |
This is specific to the GLCD display |
|
40 |
Set column number to be 40 , 32, 30 etc. This is specific to the GLCD display |
|
64 |
MAX_ROW_PIXEL the physical matrix length (y direction) This is specific to the GLCD display |
|
240 |
MAX_COL_PIXEL the physical matrix width (x direction) This is specific to the GLCD display |
The GCBASIC library supports the following capabilities. Please refer to the relevant Help section and the device specific
demonstrations.
Commands Supported for the LCD and GLCD
The GLCD command set covers the standard GLCDCLS, Line, Circle and all the GLCD methods and the LCD command set: CLS, Locate,
Print, LCDHEX etc. The demonstrations show how to load BMP loading via external data sources and GLCD and LCD page swapping.
The table below shows the specific implementations of the command set for this device. Refer to the GLCD and LCD in the
Help for the generic GLCD and LCD commands.
Commands | Usage |
---|---|
CLS |
Clear the screen of the current LCD page |
LOCATE |
Locate the cursor at a specific screen position |
|
Print numbers or strings |
PUT |
Put a specific ASCII code at a specific screen position |
LCDHOME |
Set output position of 0, 0 |
LCDcmd |
Send specific command to the device to control the device. |
LCDdata |
Send specific data to the device to control the device. |
LCDHex |
Print Hex value of a number to the LCD screen |
LCDSpace |
Print a number of space to the LCD screen |
LCDCursor |
Send specific commands to the device to control the cursor |
GLCDCLS |
Clear the screen of the current GLCD page |
GLCDRotate |
Rotate the GLCD screen. Only Landscape rotation is supported. |
SelectGLCDPage_T6963 |
Select a specific GLCD page. |
SelectLCDPage_T6963 |
Select a specific LCD page. |
GLCD and LCD page swapping
To support GLCD and LCD page swapping - this can be used to support fixed pages of information, BMPs or scrolling the following
constants have are available to the user.
For GLCD memory addressing
GLCDPage0_T6963 GLCDPage1_T6963 GLCDPage2_T6963 ... etc GLCDPage10_T6963
Ten pages are automatically created but the number of pages available is constrained by the memory configuration.
For LCD memory addressing
LCDPage0_T6963 LCDPage1_T6963 LCDPage2_T6963 ...etc LCDPage10_T6963
Ten pages are automatically created but the number of pages available is constrained by the memory configuration.
To use add the following to you user program. See the demonstration programs for more detailed usage. After calling the
SelectGLCDPage
or SelectLCDPage
methods all GLCD or LCD commands will be applied to the current GLCD or LCD page.
'Select the GLCD page 1 memory SelectGLCDPage ( GLCDPage1_T6963 ) 'Select the LCD page 2 memory SelectLCDPage ( LCDPage2_T6963 )
The SelectLCDPage
and SelectLCDPage
and "Set Text Home Address" methods change the screen being viewed on the device.
The key is to establish what you want your memory map to look like. Below is a map for one of my 240 x 64 pixel device.
The default is for 10 screen pages (some newer LCD’s may have more RAM for more screens). If you write the appropriate
value (0x1000, or 0x11b0, or 0x1360, etc) to the text home address, the display will instantly change to that screen - using
SelectLCDPage
and SelectLCDPage
method with the appropiate constant as parameter.
You can write your screens "ahead of time", in my case during the "splash screen" delay interval, and instantly change to them later as desired. You can do this by setting current_grh_home_addr to the appropiate page. And, then execute the GLCD commands you would normal use.
The graphic and text screens are independant but can be overlaid for a variety of useful effects.
Although, not tested, the LCD text screens can be scrolled 1 full text line at a time, while the GLCD screens can be scrolled 1 pixel row at a time, provided you’ve set up your memory map accordingly with adequate RAM for the graphic area.
Default Memory Map
' '******************************************************* ' ' LCD MEMORY MAP ' '******************************************************* ' ' ' ' -------------------- ' | | 0x0000 ' | | ' | TEXT RAM AREA | Each page has the numnbers of bytes + extra ' | ( 10 SCREENs ) | few bytes need to attributes. This is ' | | mentioned in the datasheet but imperical ' | | testing shows... you need the extra bytes ' -------------------- ' | | ' | xx bytes unused | ' | | ' -------------------- ' | | 0x3fff ' | | ' | | ' | GCLD RAM AREA | ' | ( 10 SCREENS ) | ' | | ' | | ' | | ' -------------------- ' | | 0x77ff ' | CG RAM AREA | (Sacrosanct) ' | | ' -------------------- 0x7ffff '
Other methods and constants
There are many other methods and constants that support this device. Reviewing the library will assist in understanding
how these private methods and constants support the overal solution for this library.
For more help, see GLCDCLS, GLCDDrawChar, GLCDPrint or Pset
Supported in <GLCD.H>