W741E260 Datasheet, PDF (28/94 Pages) Winbond – 4-BIT FLASH MICROCONTROLLER

W741E260
When Fw = 32.768 KHz, the LCD frequency is as shown in the table below.
LCD Frequency
Static
1/2 Duty
1/3 Duty
1/4 Duty
Fw/512 (64 Hz)
64
32
21
16
Fw/256 (128 Hz)
128
64
43
32
Fw/128 (256 Hz)
256
128
85
64
Fw/64 (512 Hz)
512
256
171
128
Corresponding to the 32 LCD drive output pins, there are 32 LCD data RAM segments (LCDR00 to
LCDR1F). Instructions such as MOV LCDR, #I; MOV WR, LCDR; MOV LCDR, WR; and MOV LCDR,
ACC are used to control the LCD data RAM. The data in the LCD data RAM are transferred to the
segment output pins automatically without program control. When the bit value of the LCD data RAM is
"1," the LCD is turned on. When the bit value of the LCD data RAM is "0," LCD is turned off. The
contents of the LCD data RAM (LCDR) are sent out through the segment0 to segment31 pins by a
direct memory access. The relation between the LCD data RAM and segment/common pins is shown
below.
COM3
COM2
COM1
COM0
LCD Data RAM
Output Pin
bit 3
bit 2
bit 1
bit 0
LCDR00
SEG0
0/1
0/1
0/1
0/1
LCDR01
SEG1
0/1
0/1
0/1
0/1
.
.
.
LCDR1E
LCDR1F
.
.
.
SEG30
SEG31
.
.
.
.
.
.
.
.
.
.
.
.
0/1
0/1
0/1
0/1
0/1
0/1
0/1
0/1
The LCDON instruction turns the LCD display on (even in HOLD mode), and the LCDOFF instruction
turns the LCD display off. At initial reset, all the LCD segments are lit. When the initial reset state ends,
the LCD display is turned off automatically. To turn on the LCD display, the instruction LCDON must be
executed. When the drive output pins are used as DC output ports (setting by option codes, please
refer the user's manual of ASM741S assembler for more detail), CMOS output type or NMOS output
type can be selected by executing the instruction MOV LCDM, #I. The relationship between the LCD
data RAM and segment/common pins is shown below. The data in LCDR00 are transferred to the
corresponding segment output port (SEG3 to SEG0) by a direct memory access. The other LCD data
RAM segments can be used as normal data RAM to store data.
LCD Data RAM
LCDR00
LCDR03-LCDR01
LCDR04
LCDR07-LCDR05
.
.
.
LCDR1C
LCDR1F-LCDR1D
Output Pin
SEG3-SEG0
-
SEG7-SEG4
-
.
.
.
SEG31-SEG30
-
Bit 3
SEG3
-
SEG7
-
.
.
.
SEG31
-
Bit 2
SEG2
-
SEG6
-
.
.
.
SEG30
-
Bit 1
SEG1
-
SEG5
-
.
.
.
SEG29
-
Bit 0
SEG0
-
SEG4
-
.
.
.
SEG28
-
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