PCA84C646 Philips Semiconductors, PCA84C646 Datasheet - Page 27

• Manufacturer Part Number: PCA84C646
• Description: Microcontrollers for TV tuning control and OSD applications
• Manufacturer: Philips Semiconductors

Philips Semiconductors
12.3
Derivative Register 33 is to control the character blinking related operation. Figure 18 shows the timing diagram of
character blinking frequency and blinking ratio.
Table 26 Derivative Register 33
Table 27 Description of Derivative Register 33 bits
Table 28 Active ratio determined by bits BR1 and BR0
1995 Jun 15
handbook, full pagewidth
BR1
Microcontrollers for TV tuning
control and OSD applications
0
0
1
1
7 to 4
BIT
7
3
2
1
0
Derivative Register 33 (CON3)
Blinking frequency:
Blinking ratio: 1 : 3
Blinking frequency:
Blinking ratio: 1 : 1
Blinking frequency:
Blinking ratio: 3 : 1
Blinking frequency:
Blinking ratio: 1 : 3
Blinking frequency:
Blinking ratio: 1 : 1
Blinking frequency:
Blinking ratio: 3 : 1
BR0
0
1
0
1
SYMBOL
BR1
BR0
BF1
BF0
6
f
f
f
f
f
f
VSYNC
VSYNC
VSYNC
VSYNC
VSYNC
VSYNC
VSYNC
16
16
16
32
32
32
Fig.18 Example of character blinking (NTSC 525LPF/60Hz).
ACTIVE RATIO
These 4 bits are reserved.
Blinking active ratio select bits. These two bits allow one from a choice of three active
blinking ratios to be selected; see Table 28.
Blinking frequency select bits. These two bits allow one from a choice of four blinking
frequencies to be selected.
where ‘2
Blinking frequency
3 : 1 (default)
60 Hz
reserved
0
1 : 1
1 : 3
5
1
(BF1, BF0)
2 3
’ is a decimal value determined by bits BF1 and BF0; see Table 29.
7
=
8
4
--------------------------------------- - Hz
16 2
10 11
f
VSYNC
27
BF1, BF0
Table 29 Blinking frequency determined by (BF1,BF0)
BF1 BF0 2
0
0
1
1
BR1
14 15 0
3
DESCRIPTION
0
1
0
1
60 Hz
,
1
(BF1, BF0)
PCA84C646; PCA84C846
2 3
1
2
4
8
BR0
2
7
BLINKING FREQUENCY (Hz)
8
1
128
10 11
Preliminary specification
BF1
1
1
1
1
16
32
64
f
VSYNC
f
f
f
VSYNC
VSYNC
VSYNC
14 15
MRA848
(default)
BF0
0