LCD CONTROLLER/DRIVER KS57C2308/P2308/C2316/P2316
12-4
LCD CONTROL REGISTER (LCON)
The LCD control register (LCON) is used to turn the LCD display on and off, to output LCD clock (LCDCK) and
synchronizing signal (LCDSY) for LCD display expansion, and to control the flow of current to dividing resistors in
the LCD circuit. Following a RESET, all LCON values are cleared to "0". This turns the LCD display off and stops
the flow of current to the dividing resistors.
The effect of the LCON.0 setting is dependent upon the current setting of LMOD.3.
Table 12-2. LCD Control Register (LCON) Organization
LCON Bit Setting Description
LCON.3 0This bit is used for internal testing only; always logic zero.
LCON.2 0Disable LCDCK and LCDSY signal outputs.
1Enable LCDCK and LCDSY signal outputs.
LCON.1 0Always logic zero.
LCON.0 0LCD output low, display off; cut off current to dividing resistor, and output port
8 latch contents.
1If LMOD.3 = “0”:; LCD display off; output port 8 latch contents.
If LMOD.3 = “1”: COM and SEG output in display mode; LCD display on.
Table 12-3. LCON.0 and LMOD.3 Bit Settings
LCON.0 LMOD.3 COM0–COM3 SEG0–SEG31 P8.0–P8.7
0 – Output low; LCD display off Output low;
LCD display off Output latch
contents Cut off current to
dividing resistors
1 0 LCD display off LCD display off Output latch
contents LCD display off
1COM output corresponds to display
mode SEG output
corresponds to
display mode
Output latch
contents LCD display on
LCON “0” LCON.2 "0"LCON.0 F8EH