Z90251 ZILOG [Zilog, Inc.], Z90251 Datasheet - Page 44

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

5.5
Inter-Row Spacing
Inter-Row Spacing can be from 0 to 15 horizontal scan line (HL). A setting of 0
HL is called Continuous Row Display. A horizontal interrupt is generated at the
start of each row. Software must program the spacing between the current row
and the next row during the current horizontal interrrupt.
The time required to process a row must not exceed the display time of the row.
Refer to Table 20.
Table 20 Row Space Register 04h: BankA (ROW_SPACE)
Bit 7, Fade ON/OFF, disables or enables the fade effect.
Bit 6, Fade Direction, controls the direction of the fade effect. When Fade
Direction is set to 0, the bottom of the TV screen is faded out. Fading occurs
beginning with the row number set in FADE_POS1 (3,2,1,0) and the scan line
number set in FADE_POS2 (4,3,2,1,0). When the Fade Direction is set to 1,
the top of the screen is faded out.
Bits 5 and 4, Halftone Effect Delay on P20, work with MC_REG (7).
Bits 3, 2, 1, and 0, Inter-Row Space, specify the number of HL to add between
displayed rows.
Bit
R/W
Reset
Note: R = Read W = Write X = Indeterminate
Bit/
Field
Fade On/Off
Fade Direction
Halftone Effect Output
Delay On P20
Inter-Row Space
7
R/W
0
6
Bit
Position R/W
7
6
3, 2, 1, 0
5, 4
R/W
0
5
R/W
0
R/W
R/W
R/W
R/W
4
32 KB Television Controller with OSD
R/W
Value
0
0
1
0
1
3
Description
Fade feature disabled
Fade feature enabled
Fade area below the defined fade
position
Fade area above the defined
fade position
Works with bit 7 in MC_Reg
Inter row spacing
R/W
0
2
R/W
0
1
R/W
PS001301-0800
0
0
R/W
0
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