MITSUBISHI MICROCOMPUTERS
M37274EFSP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
Notes 1: An OSD interrupt does not occur at the end of display when
(11) Multiline Display
The M37274EFSP can ordinarily display 16 lines on the CRT screen
by displaying 16 blocks at different vertical positions. In addition, it
can display up to 16 lines by using OSD interrupts.
the block is not displayed. In other words, if a block is set to
off display by the display control bit of the block control reg-
ister (addresses 00D016 to 00DB16), an OSD interrupt re-
quest does not occur (refer to Figure 93 (A)).
An OSD interrupt request occurs at the point at which display of each
block has been completed. In other words, when a scanning line
reaches the point of the display position (specified by the vertical
position registers) of a certain block, the character display of that
block starts, and an interrupt occurs at the point at which the scan-
ning line exceeds the block. The mode in which an OSD interrupt
occurs is different depending on the setting of the raster color regis-
ter (refer to Figure 99).
2: When another block display appeares while one block is
displayed, an OSD interrupt request occurs only once at
the end of the another block display (refer to Figure 93 (B)).
3: On the screen setting window, an OSD interrupt occurs
even at the end of the CC mode block (off display) out of
window (refer to Figure 93 (C)).
· When bit 7 of the raster color register is “0”
An OSD interrupt occurs at the end of block display in the OSD
and the EXOSD mode.
· When bit 7 of the raster color register is “1”
An OSD interrupt occurs at the end of block display in the CC mode.
Block 1 (on display)
Block 1 (on display)
“OSD interrupt request”
“OSD interrupt request”
“OSD interrupt request”
Block 2 (on display)
Block 3 (on display)
Block 4 (on display)
Block 2 (on display)
“OSD interrupt request”
Block 3 (off display)
Block 4 (off display)
No
“OSD interrupt request”
“OSD interrupt request”
“OSD interrupt request”
No
“OSD interrupt request”
On display (OSD interrupt request occurs
at the end of block display)
Off display (OSD interrupt request does
not occur at the end of block display)
(A)
Block 1
Block 2
“OSD interrupt request”
“OSD interrupt request”
Block 1
Block 2
No
“OSD interrupt request”
“OSD interrupt request”
Block 3
“OSD interrupt request”
Window
In CC mode
(C)
(B)
Fig. 93. Note on Occurence of OSD Interrupt
93
RENESAS [ RENESAS TECHNOLOGY CORP ]
