HD66717 Datasheet, PDF (61/90 Pages) Hitachi Semiconductor – (Low-Power Dot-Matrix Liquid Crystal Display Controller/Driver)

HD66717
Segment Display and Annunciator Display
The HD66717 provides both segment display, which is driven by the multiplexing method, and
annunciator display, which is driven statically. Annunciator display is driven at a logic operating voltage
(V_CC – AGND) and is thus also available while the LCD drive power supply is turned off. Accordingly,
annunciator display is suitable for displaying marks during system standby, when it is desirable to reduce
current consumption. It is available in sleep mode, where internal multiplexing operations for character or
segment display are halted. If an alternating signal is supplied to the EXM pin, it is also available in
standby mode, where the internal R-C oscillator is halted. Here, AGND must be equal to or above the
GND level.
Note that annunciator display cannot share character display drivers SEG and COM but require special
drivers ASEG and ACOM that require long routing.
Tables 21 to 23 illustrates segment display and annunciator display.
Table 21 Comparison between Segment Display and Annunciator Display
Item
Number of driven elements
Blinking
Segment drivers
Common drivers
LCD power supply
Normal mode display
Sleep mode display
Standby mode display
(without oscillation)
Segment Display
Annunciator Display
20 each by COMS1 and COMS2
10
Impossible
Possible
SEG1–SEG60
(shared with character display)
ASEG1–ASEG10
(independent of character display)
COMS1, COMS2
ACOM
V_CC – V5
(LCD power supply necessary)
V_CC – AGND
(LCD power supply unnecessary)
Display possible together with
Display possible by static drive
character display by multiplexing drive
Impossible
(SEG and COM output V_CC)
Impossible
(SEG and COM output V_CC)
Possible by static drive
Possible by supplying alternating
signal to the EXM pin
513