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CHAPTER 18 LCD CONTROLLER/DRIVER
User’s Manual U15798EJ2V0UD
18.4 LCD Display RAM
The LCD display data and the LCD blinking select bits corresponding to the LCD display data are mapped to
addresses FA00H to FA27H. The lower 4 bits of each of these addresses are an LCD display data area, and the
higher 4 bits are an LCD blinking select bit area. The LCD blinking select bits correspond to the LCD display data
(i.e., LCD blinking select bit 0 corresponds to bit 4 of the LCD display data, bit 1 to bit 5, bit 2 to bit 6, and bit 3 to
bit 7).
The data stored to the LCD display data area can be displayed on the LCD panel. For example, bit 3 at address
FA01H (the shaded portion in Figure 18-9) is output to S1 pin at the COM3 timing.
The LCD blinking select bit is used to blink the corresponding segment by setting 1 to the bit to blink, and 1 to
bit 3 (BLON) of LCD display mode register 3 (LCDM3). In this case, however, the display data of the corresponding
segment must be 1.
Figure 18-9 shows the relationship between the LCD display data, contents of the blinking select bits, and segment/
common output signals.
The area not used for display can be used as a normal RAM area.
Figure 18-9. Relationship Between LCD Display Data, Contents of Blinking Select Bits,
and Segment/Common Output Signals (4-Time Division)
Caution The higher 4 bits (LCD blinking select bit area) of each address, FA00H to FA27H, correspond
to the lower 4 bits (LCD display data area). When the LCD does not blink, therefore, be sure to
clear the corresponding bit in the blinking select bit area to 0.
S0
S1
S2
S38
S31
S23
S39
⋅⋅⋅
⋅⋅⋅
⋅⋅⋅
FA00H
Address
Bit 7
Bit 6
LCD blinking select bit area
LCD display data area
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
COM3
COM2
COM1
COM0
SCOM0
FA01H
FA02H
FA26H
FA1FH
FA17H
FA27H
⋅⋅⋅
⋅⋅⋅
⋅⋅⋅
Example:
The LCD blinking select bit
corresponding to bit 0 at
address FA00H is bit 4 at
address FA00H.
Содержание mPD780344 Series
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