M37221M4H/M6H/M8H/MAH–XXXSP/FP M37221EASP/FP
8.11.3 Clock for OSD
The following 2 types of clocks can be selected for OSD display.
• Main clock supplied from XIN pin
• Main clock supplied from XIN pin divided by I.5
• Clock from the ceramic resonator or the LC or oscillator from the
pins OSC1 and OSC2
• Clock from the ceramic resonator or the quartz-crystal oscillator
supplied from pins OSC1 and OSC2.
The OSD clock for each block can be selected by the OSD clock
selection register (address 00ED16).
When selecting the main clock, set the oscillation frequency to
8 MHz.
OSD Clock Selection Register
b7 b6 b5 b4 b3 b2 b1 b0
OSD clock selection register (CK) [Address 00ED16
]
0
0 0 0 0 0
B
Name
Functions
After reset
0
R
R
W
W
0, 1 OSD clock
selection bits
(CK0,CK1)
Functions
b1 b0
The clock for display is supplied by connecting RC
or LC across the pins OSC1 and OSC2.
0
0
0
1
Since the main clock is used as the
clock for display, the oscillation
OSD oscillation
frequency
frequency is limited. Because of this,
the character size in width (horizontal)
direction is also limited. In this case,
pins OSC1 and OSC2 are also used
= f(XIN)
1
1
OSD oscillation
frequency
= f(XIN)/1.5
0
1
as input ports P33 and P34 respectively.
The clock for OSD is supplied by connecting the
following across the pins OSC1 and OSC2.
• a ceramic resonator only for OSD
• a quartz-crystal oscillator only for OSD and a
feedback resistor (See note
)
2 to 7 Fix these bits to “0.”
0
R
W
Note: It is necessary to connect other ceramic resonator or quartz-crystal oscillator for OSD across the pINs
XIN and XOUT.
Fig. 8.11.10 OSD clock selection Circuit
Rev.1.00 Oct 01, 2002 page 64 of 110
REJ03B0134-0100Z
RENESAS [ RENESAS TECHNOLOGY CORP ]
