------------------------------------------------------HMCS46C,HMCS46CL
These currents and added to the Stand·
by Supply Current (or Halt Current).
..
Disable"1outp.ut
.......
NMOS
Output:
OFF
CMOS
Output:
High Impedance
(NMOS, PMOS:
OFF)
Pull up
MOS
...
OFF
Input
.........
Input Circuit:
OFF
Both input and
output
are at high
impedance state.
Since an input circuit
is
OFF, any current
other
than the Stand·
by Supply Current
(or
Halt Current) does
not flow even
if
an input signal changes.
When the
m::T
pin is set
to
"I"
("High"
level), the HMCS46C
gets into operation from the status
just
before the Halt State.
The halt timing
is
shown in Figure 24.
CAUTION
If, during the Halt State, the external reset input is applied
(RESET =
"I"
("High" level», the internal status
is
not
held.
•
OSCILLATOR
The HMCS46C contains its own oscillator and frequency
divider
(CPG). The user can obtain the desired timing for opera.
tion
of
the LSI
by
merely connecting an resistor
Rf
or ceramic
filter circuit (Internal
Clock Operation). Also an external oscil·
lator can supply a clock (External
Clock Operation).
The
OSC
I
clock frequency
is
internally divided by four
to
produce the internal system clocks.
The user may exchange
the
external parts for the same LSI
to
select either
of
these two operational modes
as
shown in
Figure 25. There
is
no
need
of
specifying
it
by
using the mask
option.
The typical value
of
clock oscillation frequency (fose) varies
with a oscillation resistor Rf
as
shown in Figure 26.
I------------Halt
State-------------.,
vcc--------~~----------~
HL
T'-------
tfHLT
trHLT
OPR
Figure 24 Halt
Timing
(a)
Internal Clock Operation Using Resistor R
f
Wiring
of OSC. and
OSC
2
terminals should
R
be
81
short 81 possible because the oscillation
c(
SC.
f frequency
Is
modified by capacitance of
OSC
2
these terminals.
(b) Internal Clock Operation Using Ceramic
Filter
Circuit (This
is
not
applied
to
HMCS46CL.)
c.
~~:~iC~~~~'-~
}C
2
Ceramic Filter; CSB800A (MURATA)
R.
1MO ±
10%
C. 100pF ±
10%
(Ceramic Capacitor)
C
2
100pF ±
10%
(Ceramic Capacitor)
GND
The ceramic filter oscillation does
not
apply when using "Halt" and not
resetting
at
the
time of "Halt" cancallation.
Thil circuit il
the
exemple of the typical u
•.
AI the oscillation character·
istics il
not
guaranteed.
plea.
consider and examine the circuit constants
carefully
on
your application.
Figure 25 Clock Operation Modes
(to
be
continued)
103
To Next Page
Loading...
