Data Output - Roland SH-101 Service Manual

SH-101
5.
KEYBOARD READ
The
CPU
uses
a
4
x
8 matrix
to read the
number
and
position
of the
keys being
pressed
on
the
keyboard,
and determines
the
output
priority of the
CV
data
and
whether
new
Gate
signal
should be output according
to
the
key
mode
(LEGATO
or
NON-LEGATO)
and
the
set-
tings of the panel controls
(PORTAMENTO, ARPEG-
GIO,
GATE
/TRIG,
etc.)
6.
CLOCK CHECK
Any
variation
in
the voltage of the
Clock
signal
(LFO
or
EXT
CLK)
is
detected
at
the T1 terminal.
If
a
low Clock
signal
turns
high,
TR1
1
inverts
it
to
low and sends
it
to
the
CPU,
which then performs
the following operations.
(a)
Generates
Random
data.
(b)
Prepares the data
for
Arpeggio and Sequencer
playing.
7.
RANDOM DATA OUTPUT
The
CPU
outputs
to the
D/A
Converter
the
random
data
generated and
stored
in
step
6(a).
8.
FUNCTION SWITCH READ
The
CPU
scans
all
the function switches
in
order
to
detect
any changes made
by the
user.
If
an
On/Off
change
is
detected, the
CPU
jumps
to
the appropriate
step.
Refer
to the
flow
chart.
The
CPU
can detect the
On/Off
status of the
HOLD
function
at
both the Panel button
and
the Pedal switch.
When
the
KEY TRANSPOSE
button
is
pressed
and
a
new
key selected, the
CPU
iden-
tifies
the
key
that
was
pressed on the
keyboard and
thus
identifies
the
key
(pitch) to
be transposed.
9.
LOAD
If
a
Keyboard
key, the
LEGATO
(HOLD)
button
or
the
REST (KEY TRANSPOSE)
button
is
pressed, the
CPU
stores that information
in
the
RAM,
then
jumps
to step
12.
If
no key
or
button
is
pressed, the
CPU
jumps
directly to step 12.
10.
PLAY
In
the Play
mode,
the
CPU
reads the Sequencer
data
stored
in
the
RAM
and
prepares both the
KCV
and Gate
data, then
jumps
to
step
1
2.
11.
ARPEGGIO
If
the
CPU
detects during step 6 that the
Clock
signa
has
turned
high, the
CPU
prepares the
KCV
data accord-
ing to the order of the
key numbers
stored
in
the 4-byte
(32 keys) Arpeggio
Key
Buffer,
then
jumps
to
step 12.
If
the Clock Signal remains low, the
CPU
jumps
directly
to step 12.
12.
CV OUTPUT
During the Arpeggio and Sequencer
Play
modes,
the
CPU
sends
to the
D/A
Converter
the necessary
CV
data
for
executing the relevant
steps for
Arpeggio
or
Sequencer
playing.
During
all
other
modes,
the
TRANSPOSE
Switch
data
(L,
M
or
H)
is
either
added
to
or
subtracted from
the
Keyboard
information, and
the
resulting value
is
sent
to
the
D/A
Converter.
Examples
of
this
operation
are
shown
below.
Transpose Switch
Position
Key
CV
Data (After
D/A
Conversion)
L
M
H
H
Lowest
F
Lowest
F
Lowest
F
Highest
C
0.417V
1.417V
2.417V
5.0V
13.
GATE & LED
DATA OUTPUT
Port 2 of the
CPU
outputs the Gate,
Clock Reset
(CLK
RST) and
LED
Illumination
signals.
The Clock
Reset
signal
resets the
Clock
signal
whenever
a
key on
the key-
board
is
pressed while
either the
GATE/TRIG
Selector
is
set to
LFO
or the
ARPEGGIO mode
isactivated.
The
LED
Illumination
signal
illuminates the
LEDs
above
the
function switches, but does not illuminate the
LEDs
for
the
LFO
and powerswitches.
At
the
end
of
step
1
3,
the
CPU
returns
to
program
3
and
repeats the sequence
of steps
from
3 through 13.
PIN
CONNECTION
(Top View)
»
TMP80C49P
TOE
XTAL1
E
1
40
2
39
^|VCC(+5V)
HT1
XTAL2C
3 38
ZIP27
resetC
4 37
I]P26
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5
36
Z|P25
intC
6 35
ZIP24
eaC
7
34
^|P17
rdE
8
33
ZJP16
psenE
9
32
UP15
wrC
10 31
^|P14
aleE
DB0C
11
30
12 29
^]P13
Z|P12
DBlE
DB2E
13 28
14 27
^|P11
Z|P10
DB3|Z
DB4E
15
26
16 25
^]PS
ZlPROG
DB5E
17 24
HP23
DB6|Z
18 23
ZJP22
DB7\Z
19
22 ^|P21
SS(0V)C
20
21
^]P20
3