p87c770aar NXP Semiconductors, p87c770aar Datasheet - Page 47

• Manufacturer Part Number: p87c770aar
• Description: Microcontrollers Ntsc With On-screen Display Closed Caption
• Manufacturer: NXP Semiconductors

Philips Semiconductors
18.5.2
The scroll map allows a flexible allocation of data in the memory, to individual rows. Sixteen 12-bit words are provided in
the display memory for this purpose. The bit allocation is shown in Table 67. The scroll map memory is located in the
first 16 words in the display memory (data byte addresses 8000H to 801FH) as shown in Fig.18.
Table 67 Scroll map word format
1999 Jun 11
handbook, full pagewidth
11
10
9 to 0
Microcontrollers for NTSC TVs with On-Screen
Display (OSD) and Closed Caption (CC)
BIT
S
CROLL MAP
Text display enable, valid outside soft scroll area. A logic 0 = disable; a logic 1 = enable.
Reserved, should be set to a logic 0.
Pointer to row data.
entries
Scroll
Map
available
scrolling
rows for
display
data
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9
Display memory
Fig.18 Scroll map and data pointers.
Enable
bit = 0
47
DESCRIPTION
display possible
un-usable for
soft Scrolling
un-usable for
OSD display
OSD display
Text area
possible
possible
display
display
MGK549
10
11
10
11
12
13
14
15
ROW
0
1
2
3
4
3
4
9
Row counter
0 to 15 valid
Row counter
0 to 15 valid
Scroll counter
3 to 11 valid
P8xCx70 family
Product specification