Z90251 ZILOG [Zilog, Inc.], Z90251 Datasheet - Page 58

• Manufacturer Part Number: Z90251
• Description: eZVision 200 Television Controllers with OSD
• Manufacturer: ZILOG [Zilog, Inc.]

allowing 2286 µs to program the next row. Additional programming time is
available with inter-row spacing. VRAM is updated during that time.
If the program has too much to display, black lines appear at the top of the screen.
The HV Interrupt Status Register (Table 34) keeps track of the type of interrupt
issued, horizontal or vertical.
Table 34 HV Interrupt Status Register 07h: Bank C (INT_ST)
Bit 7, Fringe Color Selection, sets the fringe color to the background color or to a
Red, Green, and Blue color specified in bits 6,5,4.
Bit 3, Palette Mode, sets color to Normal or VRAM Mode. When the value is 0
(Normal Mode), the color attribute of a row is controlled by values in the
ROW_ATTR register which is mapped in VRAM, but the Color Palette Selection Bits
Bit
R/W
Reset
Note: R = Read W = Write X = Indeterminate
Bit/
Field
Fringe Color Selection
Fringe Color
Palette Mode
Horizontal Interrupt
Enable
Vertical Interrupt
Horizontal Interrupt
Note: The fringing feature is not available in Progressive Mode.
7
R/W
0
6
Bit
Position R/W Value Description
7
6, 5, 4
3
2
1
0
R/W
0
5
R/W
R/W
R/W
R/W
R/W
0
W
W
R
R
4
32 KB Television Controller with OSD
R/W
1
1
0
1
0
1
0
1
1
0
1
0
0
0
0
Select Character Background Color
Select Fringe Color RGB*
Defines Fringe Color RGB
Normal Mode
Color Palette Mode
No Horizontal Interrupt
Enable Horizontal Interrupt
No Vertical Interrupt
Vertical Interrupt
No Effect
Reset Vertical Interrupt Flag
No Horizontal Interrupt
Horizontal Interrupt
No Effect
Reset Horizontal Interrupt Flag
3
R/W
0
2
R/W
0
1
R/W
PS001301-0800
0
0
R/W
0
50