83C145 Datasheet, PDF (20/40 Pages) NXP Semiconductors – Microcontrollers for TV and video MTV

Philips Semiconductors
Microcontrollers for TV and video (MTV)
Product specification
83C145; 83C845
83C055; 87C055
Table 19 Special characters related to OSDT register
SPECIAL CHARACTER
New Line
Space (normal)
BSpace
SplitBspace
OSDT5
1
1
1
1
OSDT4
1
1
1
1
OSDT3
1
1
1
1
OSDT2
1
1
1
1
OSDT1
0
0
1
1
OSDT0
1
0
0
1
13.6.3 SPECIAL FUNCTION REGISTER OSAT
Table 20 Special Function Register OSAT ( On Screen ATtributes; address 98H)
WITH OSDT =
New Line
BSpace
SplitBSpace
Any other character
7
6
5
4
3
−
−
−
E
−
−
−
−
B
−
−
−
−
B
−
−
−
−
B
−
2
SR
BC2
BC2
FC2
1
D
BC1
BC1
FC1
0
Sh
BC0
BC0
FC0
Table 21 Description of OSAT bits
BIT SYMBOL
DESCRIPTION
7 to 5, 3
−
Reserved.
With OSDT = New Line; note 1
4
E
End; If the E bit is 1, no further rows are displayed on the screen.
2
SR
Short row; If E = 0 and SR = 1, the next row is a ‘short row’, i.e. it is only 4 or 8 scan lines high
rather than 18 or 36. Short rows can be used for underlined text.
1
D
Double height; If E = 0 and D = 1, all of the characters in the following row are displayed with
‘double height and width’.
0
Sh
Shadowing; If E = 0 and Sh = 1, all of the characters in the following row are displayed with
‘shadowing’; see Section 13.8.
With OSDT = BSpace or SplitBspace; note 2
4
2 to 0
B
Background; B indicates whether ‘background pixels’ should show the current background
colour (B = 1), or television video (B = 0).
BC2 to BC0 Bcolor: Background colour (notes 3 and 4; see Table 22).
With OSDT = Any other character
4
B
Background; B indicates whether ‘background pixels’ should show the current background
colour (B = 1), or television video (B = 0).
2 to 0 FC2 to FC0 Fcolor: Foreground colour. Fcolor indicates the colour of ‘foreground pixels’ in the ROM bit
map for this character (see Table 22).
1996 Mar 22
20