M3727GM6 Datasheet, PDF (69/129 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER and ON-SCREEN DISPLAY CONTROLLER

M3727GM6/M8–XXXSP/FP M37272E8SP/FP
8.11.3 Clock for OSD
As a clock for display to be used for OSD, it is possible to select one
of the following 3 types.
• Data slicer clock output from the data slicer (approximately 26 MHz)
• OSC1 clock supplied from the pins OSC1 and OSC2
• Clock from the ceramic resonator or the LC oscillator from the pins
OSC1 and OSC2
This OSD clock for each block can be selected by the following bits
: bit 7 of the raster color register (address 00D916), bits 3 to 6 of the
clock source control register (addresses 00D016). A variety of char-
acter sizes can be obtained by combining dot sizes with OSD clocks.
When not using the pins OSC1 and OSC2 for the OSD clock I/O
pins, the pins can be used as sub-clock I/O pins or port P2.
Table 8.11.2 Setting for P26/OSC1/XCIN, P27/OSC2/XCOUT
Function OSD clock Sub-clock
I/O
Register
I/O Pin
I/O Pin
Port
b7 of raster color
register
0
0
1
OSD control
b6
1
0
1
register
b5
0
0
0
Data slicer
circuit
Data slicer clock
(See note)
“0”
“1” ^OC3
“0”
Ceramic · LC
OSC1 clock
“10”
OC6, OC5
Oscillating mode for OSD
OC4
“1”
CC mode block
OSD mode block
Note : To use data slicer clock, set bit 0 of data slicer control register 1 to “1.”
Fig. 8.11.12 Block Diagram of OSD Selection Circuit
Rev.1.00 Apr 01, 2001 page 69 of 127
REJ03B0132-0100Z