452
CHAPTER 24 LCD CONTROLLER
24.5
LCD Controller Display RAM
Display RAM is a 28 x 4 bits (14 bytes) of display data memory used to generate
segment output signals.
■
Display RAM and Output Pins
The contents of display RAM are read automatically in synchronization with the common signal
selection timing and output from the segment output pins.
Each bit containing "1" is converted to the selected voltage (displayed on the LCD); the one
containing "0" is converted to the unselected voltage (undisplayed on the LCD).
As the LCD display operation is performed asynchronously with the CPU operation, display RAM
can be read from or written to at any timing. Pins not assigned as segment outputs can be used
as I/O ports & the corresponding areas of display RAM can be used as normal RAM. Table 24.5-
1 shows the relationships between duty setting/common outputs and bits used in display RAM.
Figure 24.5-1 shows how display RAM addresses are allocated for common output and segment
output pins.
Figure 24.5-1 Display RAM and Common/Segment Output Pins
Note: The number of segment output pins depends on each MCU series.
Address
n
bit3
bit2
bit1
bit0
SEG00
bit7
bit6
bit5
bit4
SEG01
n+1
bit3
bit2
bit1
bit0
SEG02
bit7
bit6
bit5
bit4
SEG03
n+2
bit3
bit2
bit1
bit0
SEG04
bit7
bit6
bit5
bit4
SEG05
:
:
:
:
:
:
:
:
:
:
:
:
n+11
bit3
bit2
bit1
bit0
SEG22
bit7
bit6
bit5
bit4
SEG23
n+14
bit3
bit2
bit1
bit0
SEG28
bit7
bit6
bit5
bit4
SEG29
n+15
bit3
bit2
bit1
bit0
SEG30
bit7
bit6
bit5
bit4
SEG31
COM3
COM2
COM1
COM0
Area and common pins used at 1/2 duty
Area and common pins used at 1/3 duty
Area and common pins used at 1/4 duty
Table 24.5-1 Relationships Between Duty Settings/Common Outputs and Display RAM Bits Used
Duty Setting
Common Output Used
Display Data Bits Used
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
1/2
COM0 to COM1 (2 pins)
-
-
❍
❍
-
-
❍
❍
1/3
COM0 to COM2 (3 pins)
-
❍
❍
❍
-
❍
❍
❍
1/4
COM0 to COM3 (4 pins)
❍
❍
❍
❍
❍
❍
❍
❍
❍
:
Used
-
:
Unused
Summary of Contents for F2 MC-8FX Family
Page 2: ......
Page 4: ......
Page 34: ...20 CHAPTER 1 DESCRIPTION ...
Page 38: ...24 CHAPTER 2 HANDLING DEVICES ...
Page 39: ...25 CHAPTER 3 MEMORY SPACE This chapter describes memory space 3 1 Memory Space 3 2 Memory Map ...
Page 56: ...42 CHAPTER 5 CPU ...
Page 73: ...59 CHAPTER 6 CLOCK CONTROLLER ...
Page 96: ...82 CHAPTER 6 CLOCK CONTROLLER ...
Page 104: ...90 CHAPTER 7 RESET ...
Page 105: ...91 CHAPTER 8 INTERRUPTS This chapter explains the interrupts 8 1 Interrupts ...
Page 174: ...160 CHAPTER 10 TIMEBASE TIMER ...
Page 184: ...170 CHAPTER 10 TIMEBASE TIMER ...
Page 218: ...204 CHAPTER 13 WATCH PRESCALER ...
Page 257: ...243 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 261: ...247 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 288: ...274 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 301: ...287 CHAPTER 17 16 BIT PPG TIMER ...
Page 316: ...302 CHAPTER 17 16 BIT PPG TIMER ...
Page 382: ...368 CHAPTER 21 UART SIO DEDICATED BAUD RATE GENERATOR ...
Page 390: ...376 CHAPTER 22 I2C ...
Page 395: ...381 CHAPTER 22 I2C ...
Page 399: ...385 CHAPTER 22 I2C ...
Page 430: ...416 CHAPTER 23 10 BIT A D CONVERTER ...
Page 476: ...462 CHAPTER 24 LCD CONTROLLER ...
Page 482: ...468 CHAPTER 25 LOW VOLTAGE DETECTION RESET CIRCUIT ...
Page 494: ...480 CHAPTER 26 CLOCK SUPERVISOR ...
Page 507: ...493 CHAPTER 27 REAL TIME CLOCK ...
Page 523: ...509 CHAPTER 27 REAL TIME CLOCK ...
Page 532: ...518 CHAPTER 27 REAL TIME CLOCK ...
Page 536: ...522 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 554: ...540 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 564: ...550 CHAPTER 29 EXAMPLE OF SERIAL PROGRAMMING CONNECTION ...
Page 595: ...581 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 596: ...582 INDEX Index ...
Page 597: ...583 INDEX ...
Page 600: ...586 Pin Function Index ...
Page 602: ......