Kenwood DP-1100 B Service Manual page 107

D P - 1 1 0 0 B II
2. IC OPERATION OF EACH CIRCUIT AND PIN DESCRIPTION
Pin
Port name
No.
21
-
30
31
32
33
34
42
Operation of IC1 ( T M P 4 7 C 4 1 N ) display board
X 2 5 - 2 0 2 0 - 0 0
1) Different display d i v i s i o n s . . . K e y s c a n a n d k e y s e n s e
s e c t i o n
T M P 4 7 C 4 1 N (IC1), a C M O S version of T M P 4 7 4 0 N (ICI 5
N M O S ) , has t h e s a m e f u n c t i o n as T M P 4 7 4 0 N e x c e p t t h a t it
has 1/2 t h e e x e c u t i o n s p e e d . In a d d i t i o n p r o v i d e d w i t h 2 0
pins of h i g h dielectric s t r e n g t h o u t p u t p o r t s , it is c a p a b l e of
directly d r i v i n g t h e FL display t u b e w i t h o u t driver.
A total of 8 3 e l e m e n t s ; t h e 9-digit FL display t u b e ( w h i c h
consists of 8 digit n u m b e r display u n i t s , 11 m o d e display
l a m p s a n d 16 c h a n n e l display lamps) are d y n a m i c a l l y driven
by IC1 ( T M P 4 7 C 4 1 N ) .
m a t r i x of the FL display t u b e .
Pins FSA-FSK c o r r e s p o n d t o a n o d e s e g m e n t s a t o k of FL
display t u b e a n d pins FD1 t o FD9 t o t h e grid pins of the
respective display digits. For key s c a n , 1 0 3 3 . 6 Hz o b t a i n e d
f r o m 4 0 9 6 - d i v i s i o n of t h e reference c l o c k signal f r e q u e n c y
4 . 2 3 3 6 M H z is used as t h e scan f r e q u e n c y . T h e s y s t e m in
w h i c h scan is m a d e t o grid G9 alone t w i c e in o n e c y c l e is
e m p l o y e d b e c a u s e of w i d e display a r e a , etc. A c c o r d i n g l y ,
s c a n to total 1 0 digits is m a d e , a n d t h e effective scan f r e ­
0
Signal
I/O Initial value
name
Power
v „
supply
TEST I
I
0
Xot/r
RESET I
HOLD I
Power
v „ ,
supply
Table 2 - 4 - 1 B s h o w s the display
Power supply (0 V)
Not used (Connected to \Z
s)
S
OSC connection pin
OSC connection pin
Initialize signal input
Not used (Connected to V
)
DD
Power supply ( + 5 V)
T a b l e 2 - 4 - 1 A
q u e n c y per digit is 1 0 3 . 4 Hz. This scan t o the 10 digits is
p e r f o r m e d in t h e order of 1st digit (FD1) — 2 n d digit (FD2) —
3 r d digit (FD3) -
digit (FD5) - 6 t h digit (FD6) -
(FD8) — 9th digit ( F D 9 ) , in w h i c h the a m o u n t of c h a n g e in
the brightness of e a c h digit is s u p p r e s s e d l o w . Fig. 2 - 4 - 1 B
s h o w s the o p e r a t i o n t i m i n g f o r e a c h s e g m e n t a n d e a c h digit,
a n d Table 2 - 4 - 1 C s h o w s the m a i n f u n c t i o n of e a c h display
division.
This system has 2 4 n o n - l o c k t y p e m e c h a n i c a l keys. The n o n -
lock t y p e keys are a r r a n g e d in a key m a t r i x , as s h o w n in Fig.
2 - 4 - 1 C .
For key scan t o t h e key m a t r i x s h o w n in Fig. 2 - 4 - 1 C , digit
pulses ( F D 4 - F D 9 ) are used as key matrix s c a n n i n g pulse.
In a d d i t i o n , after pressing a key e x c e p t the t i m e r s t a n d b y
s w i t c h , an " H " signal appears at p o r t pin R 8 3 (CHIRP) d u r i n g
a p p r o x . 0 . 0 7 2 sec.
Description
4 t h digit (FD4) - 9 t h digit (FD9) -
7 t h digit (FD7) -
5th
8 t h digit