4 control method of lcd driver, Toshiba – Toshiba TMP87CP24AF User Manual
Page 98
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TOSHIBA
TMP87CM24A/P24A
2.10.4 Control Method of LCD Driver
(1) Initial setting
Figure 2-49 shows the flowchart of initialization.
Example : To operate a 1/4 duty LCD of 40 segments x 4 com-mons
at frame frequency fc/
2
i
6
[H
z
]
LD
(LCDCR),00000001B
LD
LD
(P6CR),0FFH
(LCDCR),10000001B
; Sets LCD driving method and
frame frequency.
Boost frequency
; Sets P6 port as segment
output.
; Sets the initial value of
display data.
; Display enable
(2) Store of display data
Generally,
display
data
are
prepared
as
fixed
data
in
program
memory
and
stored
in
display
data
area by load command.
Figure 2-49. Initial Setting
of LCD Driver
Example 1 :
To display using 1/4 duty LCD a numerical value which corresponds to the LCD data
stored
in
data
memory
at
address
80
h
(when
pins
COM
and
SEG
are
connected
to
LCD as in Figure 2-50), display data become as shown in Table 2-12.
TABLE
LD
A, (BOH)
ADD
A,TABLE-$-5
LD
HL,0F80H
LD
(HL),(PC + A)
JRS
T,SNEXT
DB
11011111B, 00000110B,
11100011B, 10100111B,
00110110B, 10110101B,
11110101B, 00010111B,
11110111B, 10110111B
Figure 2-50. Example of COM, SEG
Pin Connection (1/4
Duty)
SNEXT:
Note : DB is a byte data difinition instruction.
3
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24-98
2002
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10-03