PCF8833 View Datasheet(PDF) - Philips Electronics
Part Name
Description
MFG CO.
'PCF8833' PDF : 112 Pages View PDF
Philips Semiconductors
STN RGB - 132 × 132 × 3 driver
Objective speciï¬cation
PCF8833
6.2.16 SET CONTRAST
Using the Set contrast command (SETCON) the VLCD voltage and the contrast of the LCD can be adjusted. The influence
of the VCON[6:0] register on the VLCD programming is explained in Section 6.2.31. The VCON[6:0] is a twos complement
number; see Table 26. An overview over the complete programming range of VLCD can be found in Section 15.1.
Table 25 Set contrast register bits
D/C
7
6
0
0
0
1
X
VCON6
5
1
VCON5
4
0
VCON4
3
0
VCON3
2
1
VCON2
1
0
VCON1
0
1
VCON0
DEFAULT
25H
00H
Table 26 Possible VCON values
VCON[6:0]
0111111
0111110
0111101
:
0000010
0000001
0000000
1111111
1111110
:
1000010
1000001
1000000
DECIMAL EQUIVALENT
63
62
61
:
2
1
0
−1
−2
:
−62
−63
−64
VLCD OFFSET
2520 mV
2480 mV
2440 mV
:
80 mV
40 mV
0 mV
−40 mV
−80 mV
:
−2480 mV
−2520 mV
−2560 mV
6.2.17 DISPLAY OFF
The Display off command (DISPOFF) connects all rows and columns to VSS1, i.e. all the pixels have a voltage of 0 V.
Since the reset state of the PCF8833 is Sleep_IN (see Section 6.2.8) the display will be in the off state after a reset.
The DISPOFF command can be switched off by sending the Display on command (DISPON); see Section 6.2.18.
Figure 7 shows the effects of the combination of commands BSTRON and BSTROFF with DISPON and DISPOFF.
Table 27 Display off register bits
D/C
7
6
5
4
3
2
1
0
DEFAULT
0
0
0
1
0
1
0
0
0
28H
6.2.18 DISPLAY ON
Using the Display on command (DISPON) the rows and columns are driven according to the current display data RAM
content and according to the display timing and settings.
The DISPON command is used to exit the DISPOFF state; see Section 6.2.17.
Figure 4 gives additional information on the effect of the DISPON/DISPOFF command. Figure 7 shows the effects of the
combination of commands BSTRON and BSTROFF with DISPON and DISPOFF.
2003 Feb 14
25
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