MITSUBISHI MICROCOMPUTERS
M37270MF-XXXSP
M37270EF-XXXSP, M37270EFSP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
The OSD ROM of the character font has a capacity of 12800 bytes.
(6) Memory for OSD
There are 2 types of memory for OSD : ROM for OSD (addresses
1080016 to 1567F16, 1800016 to 1E43F16) used to store character
dot data (masked) and RAM for OSD (addresses 080016 to 0FFF16)
used to specify the characters and colors to be displayed. The fol-
lowing describes each type of memory.
Since 40 bytes are required for 1 character data, the ROM can stores
up to 320 kinds of characters. The OSD ROM of the extra font has a
capacity of 1664 bytes. Since 52 bytes are required for 1 character
data, the ROM can stores up to 32 kinds of characters.
Data of the character font and extra font is specified shown in Figure
63.
➀ ROM for OSD (addresses 1080016 to 1567F16, 1800016 to
1E43F16)
The ROM for OSD contains dot pattern data for characters to be
displayed. To actually display the character code and the extra code
stored in this ROM, it is necessary to specify them by writing the
character code inherent to each character (code determined based
on the addresses in the ROM for OSD) into the RAM for OSD.
OSD ROM address of character font data
OSD ROM
AD16 AD15 AD14 AD13 AD12 AD11 AD10 AD9 AD8 AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0
address bit
Line number/character
code/font bit
Font
1
0
Line number
Character code
bit
=
=
=
“0216” to “1516”
“0016” to “13F16
0 : left font 1 : right font
Line number
Character code
Font bit
”
OSD ROM address of extra font data
OSD ROM
address bit
AD16 AD15 AD14 AD13 AD12 AD11 AD10 AD9 AD8 AD7 AD6 AD5 AD4 AD3 AD2
AD1 AD0
Line number/extra code
Font
bit
Extra code
1
1
0
0
0
0
Line number
/font bit
=
=
=
“0016” to “1916”
“0016” to “1F16”
0 : left font 1 : right font
Line number
Extra code
Font bit
Data in
OSD
ROM
Data in
OSD
ROM
Right
font
Left
font
Line
number
Line
number
Left
font
Right
font
b7
b0 b7
b0
b7
b0 b7
b0
FFFE16
FFFF16
000316
000316
000316
000316
000316
000316
0016
0116
0216
0316
0416
0516
0616
0716
000016
7FF016
7FF816
601C16
600C16
600C16
600C16
600C16
601C16
7FF816
7FF016
630016
0216
0316
0416
0516
0616
0716
0816
0916
0816
0916
000316
000316
000316
000316
000316
000316
000316
000316
000316
0A16
0B16
0C16
0D16
0E16
0F16
1016
1116
1216
1316
1416
1516
0A16
0B16
0C16
0D16
0016
0016
1016
1116
1216
1316
638016
61C016
60E016
607016
603816
601C16
600C16
000016
000316
000316
000316
1416
1516
1616
000316
000316
FFFF16
FFFE16
Character font
1716
1816
1916
000016
000016
Extra font
Fig. 63. OSD character data storing form
55
RENESAS [ RENESAS TECHNOLOGY CORP ]
