User`s manual

79
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
MITSUBISHI MICROCOMPUTERS
Rev. 1.0
M37281MAH–XXXSP,M37281MFH–XXXSP
M37281MKH–XXXSP,M37281EKSP
Bit 7 of Port P3
Direction Register
Clock Control
Register
8.11.4 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)
• Clock from the LC oscillator supplied from the pins OSC1 and OSC2
• Clock from the ceramic resonator or the quartz-crystal oscillator
from the pins OSC1 and OSC2
The clock for display to be used for OSD can be selected by bit 7 of
port P3 direction register, bit 2 and bit 1 of clock source control reg-
ister (address 021616). If the pins OSC1 and OSC2 are not used as
OSD clock input/output, these pins can be used as the sub-clock
input/output, or port P6.
Fig. 8.11.16 Clock Control Register
Table 8.11.3 Setting of P63/OSC1/XCIN, P64/OSC2/XCOUT
Bit 2
Bit 1
Clock input/
output pins
for OSD
Sub-clock
input/
output pins
0
0
0
Function
Registers
Input port
1
0
1
0
1
0
1
1
b
7
b
6
b
5
b
4
b
3
b
2
b
1
b
0
C
l
o c
k
c o n t r o
l
r e g
i
s t e r
(
C
S
)
[
A
d
d
r e s s 0 2 1 6
1 6
]
B
N
ame
F
u n c t
i
o n
s
A
f
t e r r e s e t
R
W
C
l
o c
k
C
o n t r o
l
R
e g
i
s t e r
0
C
l
o c
k
s e
l
e c t
i
o n
b
i
t
( C S 0 )
0
R
W
1, 2
0 :
D
a t a s
l
i
c e r c
l
o c
k
1 : O S C 1 c l o c k
0
R
W
70
R
W
T
est
bi
t
(See note 2)
OSC
1 osc
ill
at
i
ng mo
d
e
selection bits (CS1, CS2)
00 : 3 2
k
H
z o s c
i
l
l
a t
i
n g m o
d
e .
01 : U s e d a s i n p u t p o r t o f P 6
3
a n d P 6 4 ( S e e n o t e 1 ) .
10 : L C o s c i l l a t i n g m o d e
11 : C e r a m i c • q u a r t z - c r y s t a l
o s c i l l a t i n g m o d e
b2 b1
N
o t e 1 :
S
e t
b
i
t 7 o
f
a
d
d
r e s s 0 0
C
7
1 6 t o “ 1 ” , w
h
e n
O
S
C
1 a n
d
O
S
C
2 a r e u s e
d
a s
P
6
3
a n d P 6 4 .
2 : B e s u r e t o s e t b i t 7 t o “ 0 ” f o r p r o g r a m o f t h e m a s k a n d t h e E P R O M v e r s i o n s .
F o r t h e e m u l a t o r M C U v e r s i o n ( M 3 7 2 8 0 E R S S ) , b e s u r e t o s e t b i t 7 t o “ 1 ”
w h e n u s i n g t h e d a t a s l i c e r c l o c k f o r s o f t w a r e d e b u g g i n g .
00 0
F
i
x t
h
e s e
b
i
t s t o “ 0 . ”
0
R
W
3 to 6
0