EM78862B View Datasheet(PDF) - ELAN Microelectronics
Part Name
Description
MFG CO.
'EM78862B' PDF : 40 Pages View PDF
EM78862B
8-Bit RISC Type Microprocessor
6.8.3 LCD COM and SEG Signal
COM Signal: The number of COM pins varies according to the duty cycle in use as shown in
the following table. In 1/8 Duty mode, COM8 must be opened. In 1/9 Duty
mode, COM0 ~ COM8 pins must be used.
Duty
1/8
1/9
COM0
O
O
COM1
O
O
COM2
O
O
COM3
O
O
COM4
O
O
COM5
O
O
COM6 COM7 COM8
O
O
X
O
O
O
X = open, O = select
SEG Signal: The 60 segment signal pins are connected to the corresponding display RAM
address 00h to 3Bh. When Duty mode is at 1/8, the required data address are
only those from Com0 ~ Com7 (located within 00h ~ 3Bh). However, when
Duty mode is at 1/9, all data address from Com0 ~ Com7 (located within 00h ~
3Bh) and Com8 (located within 40h ~ 7Bh) are needed.
When a bit of display RAM is 1, a select signal is sent to the corresponding segment pin, and
when the bit is 0, a non-select signal is sent to the corresponding segment pin.
COM, SEG, and Select/Non-Select signals are illustrated below.
frame
com0
com1
com2
seg
dark
seg
light
Fig.13 LCD Waveform 1/4 Bias
Vdd
V1
V2
V3
VLCD
Vdd
V1
V2
V3
VLCD
Vdd
V1
V2
V3
VLCD
Vdd
V1
V2
V3
VLCD
Vdd
V1
V2
V3
VLCD
26 of 36 Mar.01.2005 (V1.1)
This specification is subject to change without further notice.
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