8XC196MC, MD, MH USER’S MANUAL

Internal

Reset

Signal

Reset State

Machine

Trigger

Count Complete

CLR

Q

SET

Clock

Q1

GEN_CON.0

(MH Only)

Internal External

VCC

RRST

RESET#

~200 Ω

RST Instruction

WDT Overflow

IDLPD Invalid Key

See the datasheet for minimum and maximum RRST values.

A3086-01

Figure 13-9. Internal Reset Circuitry

13.6.1 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 VSS, as

shown in Figure 13-10. The device has an internal pull-up resistor (RRST) shown in Figure 13-9. RESET# should remain asserted for at least one state time after VCC 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 VCC rises quickly.

13-10

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Intel 8XC196MH, 8XC196MD, 8XC196MC manual Generating an External Reset, Internal Reset Circuitry