Kenwood DP-1100 B Service Manual page 83

D P - 1 1 0 0 B II
2. IC OPERATION OF EACH CIRCUIT AND PIN DESCRIPTION
Pin No. Symbol
32
QDSS
QDRD
33
36 QDRE
37 QDAS
34, 35 NC
38 QDA-d
39 QDA-c
40 QDA-b QDA-b
41 QDA-a
8 6
I/O
Waveform
Input for
I " H "
demodulating sub-code signal Q.
Input used in reading the sub-code signal Q data inside internal
QDRD
memory in units of 4 bits via outputs QDA-a to QDA-d. When signal
I
n\ 5 v
QDRD becomes " H " , the next 4-bit data is set to pins QDA-a to
i n
( ) 5 m S
QDA-d after an arbitrary period from that pulse edge.
V J L - J y o V
Q D R E I ^ I S mS
Z T J _ _ . p , 5 V Z T J _ _ . p , 5 V
Enable signal output reading sub-code signal Q. When error judge­
\Li \Li J J J J 5 5 M M S S
ment of 80-bit input sub-code signal Q data is completed, those 4-bit
j-EE*M3 mS j-EE*M3 mS
data of MSB side are set to pin QDA-a to QAD-d, and output QDRE
becomes " H " .
0
( \ ( \ j \ j \ 5 V 5 V
5 mV 5 mV When 20 pulses are input to QDRD or when data Q in the next block
y o v y o v
V V 1 1
is written | before the data written in internal RAM is read out, |output
QDRE becomes " L " so that data reading is disabled.
13 mS 13 mS
Q D A S Q D A S
_ n _ n _ n _ n
With block error Data selection input for sub-code signal Q data outputs QAD-a to
QAD-d. For easier interface with the microprocessor, this input deter­
mines output data at QDA-a to b, QDRE and QDE ports.
I
^ D A T - ^
-
Not connected.
The 80-bit sub-code signal Q data, the block error judgement result of
the sub-code signal Q data output or signal QDRE, is output according
to the " L " or " H " setting of QDAS. For data transfer to the
microprocessor, QDAS is made " L " first, then the error judgement
result of data Q is transferred and signal QDRD is input with QDAS " L " .
Thus, data Q is transferred in units of 4 bits as required.
In addition, QDA-a to QDA-d are 3-state outputs, where selection bet­
ween output mode and high-impedance mode is made by " L " or " H "
— .
0 0
QDEa QDEb
H
L
H
L
(Example of wave­
form)
Description
sub-code sync pattern detection
QDAa QDAb
L QDRE
QDEa
H
QDAa QDAb
Result of judgement Output data processing
H No error Direct output
H 1-bit error of CRCC Direct output
L 1-bit error of data Q 1 -bit correction output
L Error of 2 bits or more Direct output
T a b l e 2 - 3 - 3 A
Remarks
mode selection,
QDAc QDAd
QDEb L
QDAc QDAd