ST62T42B ST Microelectronics, ST62T42B Datasheet - Page 50

• Manufacturer Part Number: ST62T42B
• Description: 8-BIT OTP/EPROM MCU WITH LCD DRIVER / EEPROM AND A/D CONVERTER
• Manufacturer: ST Microelectronics

ST62T42B/E42B
LCD CONTROLLER-DRIVER (Continued)
5.4.4 Stand by or STOP operation mode
No clock from the main oscillator is available in
STOP mode for the LCD controller, and the con-
troller is switched off when the STOP instruction is
executed. All segment and common lines are then
switched to ground to avoid any DC biasing of the
LCD elements.
5.4.5 LCD Mode Control Register (LCDCR)
Address: DCh - Read/Write
Bits 7-6 = DS0, DS1. Multiplexing ratio select bits .
These bits select the number of common back-
planes used by the LCD control.
Bits 5-3 = HF0, HF1, HF2. Oscillator select bits .
These bits allow the LCD controller to be supplied
with the correct frequency when different high
main oscillator frequencies are selected as system
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DS1
7
DS0
HF2
HF1
HF0
LF2
LF1
LF0
0
clock. Table 18 shows the set-up for different clock
crystals.
Bits 2-0 = LF0, LF1, LF2. Base frame frequency
select bits. These bits control the LCD base oper-
ational frequency of the LCD common lines.
LF0, LF1, LF2 define the 32KHz division factor as
shown in Table 21.
Table 21. 32KHz Division Factor for Base
Frequency Selection
LF2
0
0
0
0
1
1
1
1
LF1
0
0
1
1
0
0
1
1
LF0
0
1
0
1
0
1
0
1
512
386
256
192
128
96
64
Reserved
32KHz Division Factor