Intel 8XC196NT, User Manual

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8XC196NT USER’S MANUAL
12-10
Figure 12-8. Internal Reset Circuitry
12.5.1 Generating an External Reset
To reset the device, hold the RESET# pin low for at least one state time after the power supply is
within tolerance and the oscillator has stabilized. When RESET# is first asserted, the device turns
on a pull-down transistor (Q1) for 16 state times. This enables the RESET# signal to function as
the system reset.
The simplest way to reset the device is to insert a capacitor between the RESET# pin and V
SS
, as
shown in Figure 12-9. The device has an internal pull-up resistor (R
RST
) shown in Figure 12-8.
RESET# should remain asserted for at least one state time after V
CC
and XTAL1 have stabilized
and met the operating conditions specified in the datasheet. A capacitor of 4.7 µF or greater
should provide sufficient reset time, as long as V
CC
rises quickly.
A0034-02
Internal
Reset
Signal
Reset State
Machine
Trigger
Clock
Internal External
RRST
†
CLR
Q
RST Instruction
WDT Overflow
IDLPD Invalid Key
RESET#
~200
Ω
Count Complete
Q1
SET
VCC
USFR.0
OFD
(FOSC < 100 kHz)
† See the datasheet for minimum and maximum R
RST
values.