Toshiba TC9314F Manual page 32

The LCD driver control ports consist of a segment data selection port and segment data ports. Use the
OUT2 instruction with the operand [C
I/O port under the control of the SEG I/O control bit (φL2F). Setting the bit to "1" sets segment output.
Setting the bit to "0" sets the port as an I/O port.
Set the LCD driver segment data using the segment data ports (φL2E, φL2F). Set the segment data port
to "0" to turn the LCD display off and set "1" to turn the LCD display on. When FH is specified for the
segment data select port, the DISP OFF and V
DISP OFF bit can turn the whole LCD display off without setting segment data.
Setting this bit to "1" outputs the de-selected waveform from the common outputs and turns off the entire
LCD display. The segment contents are preserved. Setting the DISP OFF bit back to "0" displays the
previous LCD screen.
Segment data can be rewritten during DISP OFF. After a reset, and after CKSTP execution, the DISP
OFF bit is set to "1".
The V OFF bit allows an external power supply to be used. This is useful for changing the LCD drive
LCD
voltage.
The data are set according to the segment data select port (φL2D). Segment output pins S23~S30 are also
used for the key return timing signals for loading key matrix data. At the timing for loading the key matrix
data, the segment output is set to the V
2. LCD Driver Circuit Structure
= DH~FH] to access these ports. The LCD driver can operate as an
N
OFF bits are selected as segment-2 data (φL2FF). The
LCD
level.
LCD
32
TC9314F
2003-07-03