ST7781
11.1.28 Panel Interface Control 1 (R90h)
Panel Interface Control 1 (R90h)
RS
/WR
/RD D15 D14 D13 D12 D11 D10 D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
0
0
0
0
0
0
0
0
0
0
0
0
DIVI1 DIVI0
0
RTNI6 RTNI5 RTNI4 RTNI3 RTNI2 RTNI1 RTNI0
1
↑
1
0
0
0
1
0
0
0
0
0
0
Default value
DIVI [1:0]: Sets the division ratio of the internal clock frequency. The ST7781’s internal operation is synchronized
with the frequency divided internal clock. When DIVI[1:0] setting is changed, the width of the reference
clock for liquid crystal panel control signals is changed. The frame frequency can be adjusted by register
setting (RTNI and DIVI bits). When changing the number of lines to drive the liquid crystal panel, adjust the
frame frequency too.
DIVI[1:0]
Division Ratio
Internal Operation Clock Frequency
00
01
10
11
1
2
4
8
Fosc/1
Fosc/2
Fosc/4
Fosc/8
RTNI [6:0]: Sets 1H (line) period. This setting is enabled while the ST7781’s display operation is synchronized with
internal clock.
RTNI[6:0] Clocks/Line RTNI[6:0] Clocks/Line RTNI[6:0] Clocks/Line RTNI[6:0] Clocks/Line
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
0Ah
0Bh
0Ch
0Dh
0Eh
0Fh
10h
11h
12h
13h
14h
15h
16h
17h
18h
19h
1Ah
1Bh
1Ch
1Dh
1Eh
1Fh
0 clock
1 clock
2 clocks
3 clocks
4 clocks
5 clocks
6 clocks
7 clocks
8 clocks
20h
21h
22h
23h
24h
25h
26h
27h
28h
29h
2Ah
2Bh
2Ch
2Dh
2Eh
2Fh
30h
31h
32h
33h
34h
35h
36h
37h
38h
39h
3Ah
3Bh
3Ch
3Dh
3Eh
3Fh
32 clocks
33 clocks
34 clocks
35 clocks
36 clocks
37 clocks
38 clocks
39 clocks
40 clocks
41 clocks
42 clocks
43 clocks
44 clocks
45 clocks
46 clocks
47 clocks
48 clocks
49 clocks
50 clocks
51 clocks
52 clocks
53 clocks
54 clocks
55 clocks
56 clocks
57 clocks
58 clocks
59 clocks
60 clocks
61 clocks
62 clocks
63 clocks
40h
41h
42h
43h
44h
45h
46h
47h
48h
49h
4Ah
4Bh
4Ch
4Dh
4Eh
4Fh
50h
51h
52h
53h
54h
55h
56h
57h
58h
59h
5Ah
5Bh
5Ch
5Dh
5Eh
5Fh
64 clocks
65 clocks
66 clocks
67 clocks
68 clocks
69 clocks
70 clocks
71 clocks
72 clocks
73 clocks
74 clocks
75 clocks
76 clocks
77 clocks
78 clocks
79 clocks
80 clocks
81 clocks
82 clocks
83 clocks
84 clocks
85 clocks
86 clocks
87 clocks
88 clocks
89 clocks
90 clocks
91 clocks
92 clocks
93 clocks
94 clocks
95 clocks
60h
61h
62h
63h
64h
65h
66h
67h
68h
69h
6Ah
6Bh
6Ch
6Dh
6Eh
6Fh
70h
71h
72h
73h
74h
75h
76h
77h
78h
79h
7Ah
7Bh
7Ch
7Dh
7Eh
7Fh
96 clocks
97 clocks
98 clocks
99 clocks
100 clocks
101 clocks
102 clocks
103 clocks
104 clocks
105 clocks
106 clocks
107 clocks
108 clocks
109 clocks
110 clocks
111 clocks
112 clocks
113 clocks
114 clocks
115 clocks
116 clocks
117 clocks
118 clocks
119 clocks
120 clocks
121 clocks
122 clocks
123 clocks
124 clocks
125 clocks
126 clocks
127 clocks
Description
9 clocks
10 clocks
11 clocks
12 clocks
13 clocks
14 clocks
15 clocks
16 clocks
17 clocks
18 clocks
19 clocks
20 clocks
21 clocks
22 clocks
23 clocks
24 clocks
25 clocks
26 clocks
27 clocks
28 clocks
29 clocks
30 clocks
31 clocks
Ver. 1.7
66
SITRONIX [ SITRONIX TECHNOLOGY CO., LTD. ]
