M37221M4H_15 Datasheet, PDF (73/114 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
8.11.7 Multiline Display
This microcomputer can ordinarily display 2 lines on the CRT screen
by displaying 2 blocks at different vertical positions. In addition, it can
display up to 16 lines by using OSD interrupts.
An OSD interrupt request occurs at the point at which that 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.
Note: An OSD interrupt does not occur at the end of display when the block is
not displayed. In other words, if a block is set to display off by the display
control bit of the OSD control register (address 00EA16), an OSD inter-
rupt request does not occur (refer to Figure 8.11.16).
Block 1 (on display)
“OSD interrupt request”
Block 1 (on display)
“OSD interrupt request”
Block 2 (on display)
“OSD interrupt request”
Block 2 (on display)
“OSD interrupt request”
Block 1’ (on display)
Block 2’ (on display)
“OSD interrupt request”
“OSD interrupt request”
Block 1’ (off display)
Block 2’ (off display)
No
“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)
Fig. 8.11.16 Note on Occurence of OSD Interrupt
Rev.1.00 Oct 01, 2002 page 71 of 110
REJ03B0134-0100Z