PCA8514T PHILIPS [NXP Semiconductors], PCA8514T Datasheet - Page 11

• Manufacturer Part Number: PCA8514T
• Description: Stand-alone OSD
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
8
The display RAM is organized as 256
general format of each RAM location is as follows.
Bits <11-5> hold character data and allow a choice from
125 customer designed character fonts to be selected or
one of three reserved codes. Bits <4-0> contain the
attributes of the character font, for example colour,
character size etc.
8.1
There are four data formats for display RAM code:
1. Character Font Code
2. Test Code
3. Carriage Return Code
4. Space Code.
The above data formats allow great flexibility in the
creation of On Screen Displays; see Fig.8.
8.1.1
If bits <11-5> are in the range (00H to 7CH), then this is a
Character Font Code. 1 of 125 customer designed
character fonts can be selected. Bits <4-1> determine the
colour of the character, a choice of 16 colours being
available. Bit <0> determines whether the character blinks
or not. The format of the Character Font Code is shown in
Table 2.
8.1.2
If bits <11-5> hold 7DH, then this is a special code
reserved for testing purposes only.
Table 2 Format of Character Font Code
Table 3 Format of Carriage Return Code
Table 4 Format of Space Code
1995 Nov 27
Stand-alone OSD
C6
C6
C6
11
11
11
DISPLAY RAM ORGANIZATION
Description of display RAM codes
C
T
EST CODE
HARACTER FONT CODE
C5
C5
C5
10
10
10
Character Font Code (00H - 7CH)
Carriage Return Code (7EH)
C4
C4
C4
9
9
9
Space Code (7FH)
C3
C3
C3
8
8
8
12 bits. The
C2
C2
C2
7
7
7
C1
C1
C1
6
6
6
11
8.1.3
If bits <11-5> hold 7EH, then this is the Carriage Return
Code. A transparent pattern will be displayed on the
screen and the next character will be displayed at the
beginning of the next line. Bits <4-3> select the size of the
characters to be displayed on the next line. Bits <2-1>
determine the spacing between lines of displayed
characters. Bit <0> is the End of Display bit and indicates
the end of display of the current screen before exhaustion
of display RAM (i.e. before the 256th RAM location). The
format of the Carriage Return Code is shown in Table 3.
8.1.4
If bits <11-5> hold 7FH, then this is the Space Code.
A transparent pattern, equal to one character width, will be
displayed on the screen. A mask programmable option is
available that allows the space character to be transparent
or to have a programmable background colour;
see Section 13.1. Bits <4-1> determine the background
colour of the characters that follow the Space Code in both
the Box shadowing and North-West shadowing modes.
Bit <0> is the Active Character Monitor (ACM)
enable/disable bit. The ACM signal is specifically for use in
camrecorder applications where part of the display is to be
recorded on tape and displayed on the screen, whilst the
remaining part is for display only. Figure 9 shows a typical
ACM application. During the back-tracing period R, G, B, I,
FB and ACM are inactive. The format of the Space Code
is shown in Table 4.
C0
C0
C0
5
5
5
C
S
PACE CODE
ARRIAGE RETURN CODE
Character size
T4
T4
T4
4
4
4
Background colour
Foreground colour
T3
T3
T3
3
3
3
Line Spacing
T2
T2
T2
2
2
2
Product specification
PCA8514
T1
T1
T1
1
1
1
ACM
Blink
End
T0
T1
T0
0
0
0