M306V5ME-XXXSP Datasheet, PDF (182/262 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER and ON-SCREEN DISPLAY CONTROLLER

MITSUBISHI MICROCOMPUTERS
M306V5ME-XXXSP
M306V5EESP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
2.16.6 Memory for OSD
There are 2 types of memory for OSD : OSD ROM (addresses 9000016 to AFFFF16) used to store
character dot data and OSD RAM (addresses 040016 to 13FF16) used to specify the kinds of display
characters, display colors, and SPRITE display. The following describes each type of memory.
(1) ROM for OSD (addresses 9000016 to AFFFF16)
The dot pattern data for OSD characters is stored in the character font area in the OSD ROM and the
CD font data for OSD characters is stored in the color dot font area in the OSD ROM. To specify the
kinds of the character font and the CD font, it is necessary to write the character code into the OSD
RAM.
For character font, there are the following 2 mode.
• OSDL enable mode
16 ! 20-dot font and 24 ! 32-dot font
• OSDL disable mode
16 ! 20-dot font
The modes are selected by bit 3 of the OSD control register 3 for each screen.
The character font data storing address for OSDL enable/OSDL disable mode are shown in Figures
2.16.20 and 2.16.21. The conditions for each OSDL enable/disable mode are shown in Figure
2.16.22. The CD font data storing address is shown in Figure 2.16.23.
OSD control register 4
b7 b6 b5 b4 b3 b2 b1 b0
Symbol
OC4
Address
025F16
When reset
XXXXX002
Bit symbol
Bit name
Function
RW
OC40
OSDL mode
selection bit
0 : OSDL enable mode
1 : OSDL disable mode
OC41
Number of horizontal
display characters
selection bit
0 : 32 characters for each block
(32-character mode)
1 : 42 characters for each block
(42-character mode)
Nothing is assigned.
In an attempt to write to these bits, write “0.” The value, if read, turns out to be “0.”
Figure 2.16.19 OSD control register 4
182
Rev. 1.0