M37221M4H_15 Datasheet, PDF (56/114 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER with ON-SCREEN DISPLAY CONTROLLER

M37221M4H/M6H/M8H/MAH–XXXSP/FP M37221EASP/FP
8.11 OSD FUNCTIONS
Table 8.11.1 outlines the OSD functions. This microcomputer incor-
porates an OSD control circuit of 24 characters ✕ 2 lines. OSD is
controlled by the CRT control register. Up to 256 kinds of characters
can be displayed. The colors can be specified for each character and
up to 4 kinds of colors can be displayed on one screen. A combina-
tion of up to 8 colors can be obtained by using each output signal (R,
G, and B).
Characters are displayed in a 12 ✕ 16 dots configuration to obtain
smooth character patterns (refer to Figure 8.11.1).
The following shows the procedure how to display characters on the
CRT screen.
➀ Write the display character code in OSD RAM.
➁ Specify the display color by using the color register.
➂ Write the color register in which the display color is set in OSD
RAM.
④ Specify the vertical position by using the vertical position register.
➄ Specify the character size by using the character size register.
⑥ Specify the horizontal position by using the horizontal position
register.
⑦ Write the display enable bit to the designated block display flag of
the CRT control register. When this is done, the OSD starts ac-
cording to the input of the VSYNC signal.
Table 8.11.1 Features of Each Display Mode
Parameter
Number of display characters
Dot structure
Kinds of characters
Kinds of character sizes
Attribute
Character font coloring
Character background coloring
OSD output
Display position
Display expansion (multiline display)
Functions
24 characters ✕ 2 lines
12 ✕ 16 dots
256 kinds
3 kinds
Border (black)
1 screen : 8 kinds (per character unit)
1 screen : 8 kinds (per character unit)
R, G, B
Horizontal: 64 levels, Vertical: 128 levels
Possible
Rev.1.00 Oct 01, 2002 page 54 of 110
REJ03B0134-0100Z