W741E260 Datasheet, PDF (27/94 Pages) Winbond – 4-BIT FLASH MICROCONTROLLER

W741E260
LCD Controller/Driver
The W741E260 can directly drive an LCD with 32 segment output pins and 4 common output pins for a
total of 32 × 4 dots. Option codes can be used to select one of five options for the LCD driving mode:
static, 1/2 Bias 1/2 duty, 1/2 Bias 1/3 duty, 1/3 Bias 1/3 duty, or 1/3 Bias 1/4 duty (see Figure 13). The
alternating frequency of the LCD can be set as Fw/64, Fw/128, Fw/256, or Fw/512. In addition, option
codes can also be used to set up four of the LCD driver output pins (segment 0 to segment 31) as a
DC output port. The structure of the LCD alternating frequency (FLCD) is shown in Figure 12.
Fosc or Fosc/32
Fs
Fw
Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9
Fw/64
Fw/128
Mask Option
(Single/Dual Clock)
Fw/256
Fw/512
Selector
FLCD
Figure 12. LCD Alternating Frequency (FLCD) Circuit Diagram
LCD frequency
selection
Fw
Clock
Generator
DH1
DH2
VDD
VSS
LCD Voltage
Controller
VDD1 to 3
Option Codes
Data Bus
LCD Mode
Controller
LCD drive
mode
selection
FLCD
LCD duty & bias
LCD
Commom ^waveform
Driver
LCD DATA RAM
(32 x 4 bits)
MOV LCDM,#I
instruction
Segment
Driver/Controller
COM0 to 3
SEG0 to 31
Figure 13. LCD Driver/Controller Circuit Diagram
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Publication Release Date: March 1998
Revision A2