SAA5531 Philips Semiconductors, SAA5531 Datasheet - Page 78

• Manufacturer Part Number: SAA5531
• Description: Enhanced TV microcontrollers with On-Screen Display OSD
• Manufacturer: Philips Semiconductors

Philips Semiconductors
19.12 Redefinable characters
A number of Dynamically Redefinable Characters (DRC)
are available. These are mapped onto the normal
character codes, and replace the predefined ROM value.
There are 32 DRCs, the first 16 occupy the character
codes 80H to 8FH, the second 16 occupy the locations
90H to 9FH. This allows for 32 DRCs or 16 Special DRCs.
2000 Feb 23
handbook, full pagewidth
Enhanced TV microcontrollers with
On-Screen Display (OSD)
address (HEX)
8BC0
8BDF
8BE0
8BFF
881F
883F
885F
8800
8820
8840
CHARACTER 30
CHARACTER 31
CHARACTER 0
CHARACTER 1
CHARACTER 2
Fig.38 Organisation of DRC RAM.
character code
80H
81H
82H
9EH
9FH
78
The remapping of the standard OSD to the DRCs is
activated when the TXT20.DRCS ENABLE bit is set.
The selection of Normal or Special OSD symbols is
defined by the TXT20.OSD PLANES.
Each character is stored in a matrix of 12
(V
matrices to be defined within a single location.
H
character 0
A
planes), this allows for all possible character
12 bits
MBK969
address (HEX)
00
01
02
03
04
05
06
07
08
09
0A
0B
0C
0D
0E
0F
Preliminary specification
SAA55xx
16
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