Lucent Technologies MN10285K - Manual (Page 154)

On-Screen Display
Description
MN102H75K/F75K/85K/F85K LSI User Manual Panasonic Semiconductor Development Company
153
Panasonic
7 On-Screen Display
If you use the OSD function, the
DMA function executes for both
the text and graphics layers,
even if your program does not
use one of these layers. To pre-
vent error, program data for the
unused layer to meet the restric-
tions outlined here.
7.1 Description
The MN102H75K/85K contains an on-screen display (OSD) function composed
of three layers: a text layer, a graphics layer, and a cursor layer. You can control
each layer individually, which gives you great freedom in positioning displays.
You can also modify the ROM space that contains the text characters and the
graphic tiles and the VRAM space that contains the text and graphics programs.
This allows you to adjust the memory space to fit your application.
7.2 Features
Table 7-1 OSD Functions and Features
Function/Feature Text Layer Graphics Layer
Characters or tiles per line (1) 38 characters per line (2) 18 or 28 tiles per line (3)
RAM usage 80 bytes per line
Line-by-line basis
Maximum 64 lines
40 or 64 bytes per line
Line-by-line basis
Maximum 64 lines
ROM usage 36 bytes per character 16 colors: 128 bytes per tile (4)
8 colors: 96 bytes per tile
4 colors: 64 bytes per tile
2 colors: 32 bytes per tile
Max. characters or tiles 1024 characters 512 tiles (in all color modes)
Resolution 16 (wide) x 18 (high) pixels
In closed-caption mode:
16 (W) x 26 (H) (underlining is in the hardware) 16 (W) x 16 (H) pixels, or
16 (W) x 18 (H) pixels
Color depth One 16-color palette out of 4096 colors Two 16-color palettes out of 4096 colors
(Total 32 colors in one display)
Display start position (5) H: 1 dot resolution, 1024 steps
V: 1 H scan line resolution, 1024 steps
H: 1 dot resolution, 1024 steps
V: 1 H scan line resolution, 1024 steps
Character or tile size
(5)
16 character sizes, line-by-line basis
H: 1x, 2x, 3x, 4x
V: 1x, 2x, 4x, 6x
16 character sizes, line-by-line basis
H: 1x, 2x, 3x, 4x
V: 1x, 2x, 4x, 6x
Display functions • Shutter effect
• Outlining
• Shadowing (foreground and background)
• Blinking
In closed-caption mode:
• Italics
• Underlining
• Repeated tile or blank
(6)
Cursor layer Selects one tile from the graphic tile area (16 x 16)
Display position: H: 1 dot resolution, 1024 steps
V: 1 H scan line resolution, 1024 steps
Notes: 1. Maximum 60 characters + tiles in one line (when using a 64-byte graphics line). For example,
(1) If a graphics line contains 28 tiles, then the corresponding line in the text layer can only contain 32 characters.
(2) If a text line contains 38 characters, then the corresponding line in the graphics layer can only contain 22 tiles.
2. Maximum 38 characters per line (60 characters + tiles) with the default text colors. Each color assignment, including outlining
and blinking, decreases this total by one.
3. The maximum number of tiles per line is programmable in the GEXTE bit of the OSD2 register. 18 tiles requires 40 bytes per
line, and 28 tiles requires 64 bytes per line. The setting applies to all lines.
4. Multiple modes cannot be used simultaneously — the color mode applies to the entire display.
5. The OSD dot clock frequency controls the horizontal position and size. For details, see section 7.9.4, “Setting Up the OSD Dis-
play Position,” on page 180, and section 7.11, “Selecting the OSD Dot Clock,” on page 186.
6. This function can be used for a wallpapering effect or to insert spaces. One tile code can be repeated up to 16 times. Repeating
tiles allows you to use more than 18 (or 28) tiles per line.
7. For the OSD block to operate correctly, always set bit 7of the PCNT2 register (x’00FF92’) to 0.