Z8F1680SH020SG Datasheet, PDF (56/412 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F1680 Series
Product Specification
31
Chapter 5. Reset, Stop Mode Recovery
and Low-Voltage Detection
The Reset Controller within the F1680 Series MCU controls Reset and Stop Mode
Recovery operations and provides indication of low-voltage supply conditions. During the
operation, the following events cause a Reset:
• Power-On Reset (POR)
• Voltage Brown-Out (VBO) protection
• Watchdog Timer (WDT) time-out (when configured by the WDT_RES Flash option bit
to initiate a Reset)
• External RESET pin assertion (when the alternate RESET function is enabled by the
GPIO register)
• On-Chip Debugger initiated Reset (OCDCTL[0] set to 1)
When the device is in STOP Mode, a Stop Mode Recovery is initiated by each of the
following:
• Watchdog Timer time-out
• GPIO Port input pin transition on an enabled Stop Mode Recovery source
• Interrupt from a timer or comparator enabled for STOP Mode operation
The low-voltage detection circuitry on the device features the following:
• The low-voltage detection threshold level is user-defined
• It generates an interrupt when the supply voltage drops below a user-defined level
5.1.
Reset Types
The F1680 Series MCU provides various types of Reset operation. Stop Mode Recovery is
considered a form of Reset. Table 9 lists the types of Reset and their operating characteris-
tics. The System Reset is longer, if the external crystal oscillator is enabled by the Flash
option bits allowing additional time for oscillator start-up.
PS025015-1212
P R E L I M I N A R Y Reset, Stop Mode Recovery and Low-Voltage