DP-11D0B/II 0P-1100B II
F i g . 1 - 5 - 1 9
1 . T h e r e are f o l l o w i n g t w o c a s e s w h e r e m u t i n g o u t p u t is re
q u i r e d . O n e is d u r i n g all m o d e s e x c e p t t h e n o r m a l PLAY
m o d e , a n d t h e o t h e r is w h e n a d e q u a t e c o r r e c t i o n or c o m
p e n s a t i o n f o r n o r m a l p l a y b a c k c a n n o t be s e c u r e d b e c a u s e
of t o o m a n y e r r o r s c o n t a i n e d in t h e EFM signal d e p e n d i n g
o n t h e c o n d i t i o n of a disc e v e n if it is n o r m a l l y b e i n g
p l a y e d . T h e m u t i n g c a n be m a d e by the f o l l o w i n g t w o
m e t h o d s . O n e m e t h o d is t o m u t e t h e last o u t p u t stage of
t h e a n a l o g signal by u s i n g a relay a n d t h e o t h e r is to t u r n
OFF t h e 1 6 - b i t digital signal in t h e p r o c e s s c i r c u i t . For this
r e a s o n , t h e f o r m e r is c a l l e d a n a l o g m u t i n g a n d t h e latter is
called digital m u t i n g .
2 . Pin 3 8 of IC15 ( T C 1 5 G or T 7 0 0 1 ) is at " L " level d u r i n g
all m o d e s e x c e p t n o r m a l PLAY m o d e a n d it p r o v i d e s 0 V t o
t h e base of Q 4 . Q 4 is t u r n e d OFF, m a k i n g relay RL1 OFF.
T h e o u t p u t is t h u s m u t e d . A t the s a m e t i m e , pin 3 4 of IC6
( T C 9 1 7 9 F ) is also held at " L " level t h r o u g h R 1 0 3 . T h e
o u t p u t of 1 6 - b i t digital signal is t u r n e d OFF inside IC6.
3. W h e n b a d c o n d i t i o n s o f a disc ( s c r a t c h e s or dust) m a k e
t h e a d e q u a t e c o r r e c t i o n a n d c o m p e n s a t i o n i m p o s s i b l e
b e c a u s e of t o o m a n y e r r o r s in t h e EFM signal e v e n d u r i n g
n o r m a l PLAY m o d e , pin 3 5 a n d 3 6 b e c o m e " L " level. Pin
3 4 of IC6 t u r n s to " L " level by a w i r e d OR c o n n e c t i o n .
T h e digital m u t i n g is t h u s a c c o m p l i s h e d by t u r n i n g the
1 6 - b i t digital signal OFF.
1. CIRCUIT DESCRIPTION
1 - 5 - 1 9 . M U T I N G C I R C U I T O P E R A T I O N
Summary of Contents for DP-1100 B
Page 3: ...D P 1 1 0 0 B II D P 1 1 0 0 B II I BLOCK DIAGRAM ...
Page 32: ...D P 1 1 0 0 B II 1 CIRCUIT DESCRIPTION Disc Scratch Dust RFES D C O N D O C K Fig 1 2A 3 5 ...
Page 112: ...2 IC OPERATION OF EACH CIRCUIT AND D P 1 1 0 0 B II PIN DESCRIPTION Fig 2 4 1 G 1 ...
Page 117: ...DP 1100B II I OPERATION OF MAIN MICROPROCESSOR Fig 3 1D Q data reading flow chart ...