1995 Jan 19
22
Philips Semiconductors
Preliminary specification
Stand-alone OSD
PCA8515
9.9
Command 8
Table 27
Command 8 format
Command 8 loads Control Register 2 with data that
selects the input polarity of HSYNC and VSYNC (see
Fig.14) and also selects the Display modes.
Table 28
Selection of input polarity of HSYNC/VSYNC
Table 29
Selection of Display Mode
BS1
BS0
7
6
5
4
3
2
1
0
0
1
0
1
0
1
Hp
Vp
S1
S0
Hp/Vp
INPUT POLARITY
0
1
active LOW (the default setting)
active HIGH
S1
S0
DISPLAY MODE
0
0
Mode 0: this is the No background
mode. The OSD characters are
superimposed on the TV video signals
(see Fig.15).
Mode 1: this is the North West
shadowing mode; available only with
character sizes 2V/2H or 4V/4H. The
shadows are generated as if a light
source was placed North West of the
character (see Figs 16 to 18). The
shadows generated lie within 18 rows
in a vertical direction but can be
extended by one bit to the next
characters first column, in a horizontal
direction (see Figs 19 and 20).
Mode 2: this is the Box shadowing
mode. A background dot matrix of
12
×
18 bits surrounds the character
font; see Figs 21 and 22.
Mode 3: this is the Frame shadowing
(raster blanking) mode. A background
colour fills the whole screen when no
bit patterns are being displayed (see
Fig.23). 1 of 16 background colours
can be selected using Command F;
the default background colour is
BLUE.
0
1
1
0
1
1
9.10
Command 9
Table 30
Command 9 format
This command loads Control Register 3 with data that
controls both the character blinking frequency and the
active ratio of the character blinking frequency.
Figures 25 to 29 show how blinking influences the display
in different display modes.
Table 31
Selection of blinking frequency
Table 32
Selection of active ratio of character blinking
BS1
BS0
7
6
5
4
3
2
1
0
0
1
0
1
1
0
BF1
BF0
BR1 BR0
BF1
BF0
BLINKING FREQUENCY (Hz)
0
0
; this is the default setting
0
1
1
0
1
1
BR1
BR0
ACTIVE RATIO
0
0
1
1
0
1
0
1
3 : 1 (the default setting)
1 : 1
1 : 3
reserved
f
16
----------------
f
----32
f
64
-----------------
f
128
-----------------