em6324qysp5b-2.8 EM Microelectronic, em6324qysp5b-2.8 Datasheet - Page 9

• Manufacturer Part Number: em6324qysp5b-2.8
• Description: Reset Circuit With Manual Reset And Watchdog
• Manufacturer: EM Microelectronic

Functional Description
Reset Outputs
A microprocessor (µP) reset input starts the µP in a
known state. The EM6323/24 µP supervisory circuits
assert a reset to prevent code-execution errors during
power-up, power-down, and brownout conditions.
is guaranteed to be a logic low for V
Once V
keeps
(t
If a brownout condition occurs (V
threshold),
asserted it stays low for the reset timeout period. Any
time V
timer restarts.
Copyright © 2006, EM Microelectronic-Marin SA
09/06 - rev.J
POR
); after this interval,
RESET
V
WDI
MR
DD
RESET
DD
DD
goes below the reset threshold the internal
exceeds the reset threshold, an internal timer
RESET
t
POR
low for the specified reset timeout period
RESET
goes low. Each time
t < t
is the inverse of RESET.
WD
RESET
returns high.
t > t
DD
WD
dips below the reset
DD
down to 0.9V.
RESET
t
POR
is
RESET
High Impedance
9
Manual Reset Input (EM6323 only)
A logic low on
asserted while
EM6323 C-G-L-Q) after it returns high.
internal 30kΩ pull-up resistor, so it can be left open if
unused. This input can be driven with CMOS logic levels
or with open-drain outputs. Connect a normally open
momentary switch from
reset function; debounce circuitry is integrated. If
driven from long cable or the device is used in a noisy
environment, connect a 0.1μF capacitor from
to provide additional noise immunity (stronger external
additional pull-up resistor can also be added).
MR
MR
asserts a reset. Reset remains
is low, and for t
MR
EM6323/24
to V
www.emmicroelectronic.com
SS
POR
t
POR
to create a manual-
(200ms nominal for
MR
has an
MR
MR
to V
Fig. 14
is
SS