Philips PM 3266 - Page 122

127
3. 2.8.
3.
Pulse
Generation
and
Control
for
Storage
Modes
This
section
describes
how
the
storage
pulses
are
generated
in
the
different
positions
of the
pushbutton,
controls,
STORE,
WRITE,
FAST,and
their
effects
on the
various
circuit
blocks
described
in the
previous
section.
For
a fuller
explanation
of
the
functions
of any
of these
circuit
blocks,
the
reader
is referred
to this
section
3.
2.8.2.
Functions
of Storage
Circuit
Blocks.
Before
describing
the
various
modes,
a truth
table
is given in
Fig.
3.13.,
which
shows
the
generation
of the
decoding
pulses for
each of
the
modes.
PUSHBUTTON
SWITCH
DECODER
TRUTH
TABLE
MODE
D2202-2
D2202-1B 02202-12
D2202-4 D2202-6
2202-10
D2204
12 13
I/p
5
4
D2204
WRITE
15
OUTPUT MODE
PULSES
FAST STORE NON-STORE
10
7
2
NAND GATE
D2207-1
SETS
TIMER
FF D2208
FAST 1
0 0
0
1 1
0
0 0 0
0
0 1
WRITE
0
0 1
0
0 0
0
1
0 0
0
1
STORE 0
0 1 1
1
0 0 1 0 0
0
0
0
MEM
OFF
0
1 1 1
0 0 0 0 1 0
0
0 1 0
Fig. 3.
13.
Pushbutton
switch
Decoder.