UPD78F9418A NEC, UPD78F9418A Datasheet - Page 202

• Manufacturer Part Number: UPD78F9418A
• Description: (UPD7894xxA) 8-Bit Single Chip Microcontrollers
• Manufacturer: NEC

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14.1 Functions of LCD Controller/Driver
202
The functions of the LCD controller/driver of the µ PD789407A and 789417A Subseries are as follows.
(1)
(2)
(3)
(4)
(5)
(6)
Table 14-1 lists the maximum number of pixels that can be displayed in each display mode.
Notes 1. Three-digit LCD panel, each digit having an 8-segment
1/2
1/3
Bias Mode
Automatic output of segment and common signals based on automatic display data memory read
Five different display modes:
• Static
• 1/2 duty (1/2 bias)
• 1/3 duty (1/2 bias)
• 1/3 duty (1/3 bias)
• 1/4 duty (1/3 bias)
Four different frame frequencies, selectable in each display mode
Up to 28 segment signal outputs (S0 to S27) and four common signal outputs (COM0 to COM3)
Of these segment signal outputs, 12 outputs can be switched to I/O ports in 2-output units (P80/S27 to
P87/S20 and P90/S19 to P93/S16).
Voltage divider resistors (for LCD drive voltage generation) that a port itself can contain if so specified with a
mask option
Operation with a subsystem clock
−
2. Seven-digit LCD panel, each digit having a 4-segment
3. Nine-digit LCD panel, each digit having a 3-segment
4. Fourteen-digit LCD panel, each digit having a 2-segment
Static
2
3
3
4
Number of Time Slices
CHAPTER 14 LCD CONTROLLER/DRIVER
Table 14-1. Maximum Number of Pixels
COM0 (COM1 to
COM3)
COM0, COM1
COM0 to COM2
COM0 to COM2
COM0 to COM3
Common Signals
User’s Manual U13952EJ3V0UD
Used
28 (28 segment signals, 1 common signal)
56 (28 segment signals, 2 common signals)
84 (28 segment signals, 3 common signals)
112 (28 segment signals, 4 common signals)
configuration.
configuration.
configuration.
configuration.
Maximum Number of Pixels
Note 1
Note 2
Note 3
Note 4