M37281EKSP Datasheet, PDF (71/172 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER and ON-SCREEN DISPLAY CONTROLLER

M37281MAH–XXXSP,M37281MFH–XXXSP,M37281MKH–XXXSP, M37281EKSP
8.11.1 Triple Layer OSD
Three built-in layers of display screens accommodate triple display
of channels, volume, etc., closed caption, and SPRITE displays within
layers 1 to 3.
The layer to be displayed in each block is selected by bit 0 or 1 of the
OSD control register 2 for each display mode (refer to Figure 8.11.7).
Layer 3 always displays the SPRITE display.
When the layer 1 block and the layer 2 block overlay, the screen is
composed (refer to Figure 8.11.5) with layer mixing by bit 6 or 7 of
the OSD control register 1, as shown in Figure 8.11.3. Layer 3 al-
ways takes display priority of layers 1 and 2.
Notes 1: When mixing layer 1 and layer 2, note Table 8.11.2.
2: OUT2 is always ORed, regardless of values of bits 6, 7 of the OSD
control register 1. And besides, even when OUT2 (layer 1 or layer 2)
overlaps with SPRITE display (layer 3), OUT2 is output.
Table 8.11.2 Mixing Layer 1 and Layer 2
Parameter
Display mode
Pre-divide ratio
Dot size
Block
Horizontal display start position
Vertical display start position
Block in Layer 1
Block in Layer 2
CC, OSD, CDOSD mode
OSD, CDOSD mode
✕ 1, ✕ 2 (CC mode)
✕ 1 to ✕ 3 (OSD, CDOSD mode)
Same as layer 1
1TC ✕ 1/2H, 1TC ✕ 1H
(CC mode)
1TC ✕ 1H, 1TC ✕ 1/2H,
2TC ✕ 2H, 3TC ✕ 3H
(OSD, CDOSD mode)
Pre-divide ratio = ✕ 1
Pre-divide ratio = ✕ 2
1TC ✕ 1/2H
1TC ✕ 1H
1TC ✕ 1/2H, 1.5TC ✕ 1/2H
1TC ✕ 1H, 1.5TC ✕ 1H
• Same size as layer 1
• 1.5TC can be selected only when: layer 1’s pre-divide ratio = ✕ 2
AND layer 1’s horizontal dot size = 1TC.
As this time, vertical dot size is the same as layer 1.
Arbitrary
Same position as layer 1
Arbitrary
However, when dot size is 2TC ✕ 2H or 2TC ✕ 3H, set difference between vertical display position of
layer 1 and that of layer 2 as follows.
•2TC ✕ 2H: 2H Units
•3TC ✕ 3H: 3H Units
Rev.1.01 2003.07.16 page 71 of 170