Z8 Encore! XP
®
4K Series
Product Specification
28
Table 12. Reset Status Register (RSTSTAT)
BITS
FIELD
RESET
R/W
ADDR
Reset or STOP Mode Recovery Event
Power-On Reset
Reset using RESET pin assertion
Reset using Watch-Dog Timer time-out
Reset using the On-Chip Debugger (OCTCTL[1] set to 1)
Reset from STOP Mode using DBG Pin driven Low
STOP Mode Recovery using GPIO pin transition
STOP Mode Recovery using Watch-Dog Timer time-out
7
POR
R
6
STOP
R
5
WDT
R
4
EXT
0
R
FF0H
POR
1
0
0
1
1
0
0
STOP
0
0
0
0
0
1
1
WDT
0
0
1
0
0
0
1
EXT
0
1
0
0
0
0
0
0
R
3
2
Reserved
0
R
0
R
1
0
LVD
0
R
See descriptions below
POR—Power-On Reset Indicator
If this bit is set to 1, a Power-On Reset event occurred. This bit is reset to 0 if a WDT time-
out or STOP Mode Recovery occurs. This bit is also reset to 0 when the register is read.
STOP—STOP Mode Recovery Indicator
If this bit is set to 1, a STOP Mode Recovery occurred. If the
STOP
and
WDT
bits are both
set to 1, the STOP Mode Recovery occurred because of a WDT time-out. If the
STOP
bit
is 1 and the
WDT
bit is 0, the STOP Mode Recovery was not caused by a WDT time-out.
This bit is reset by a Power-On Reset or a WDT time-out that occurred while not in STOP
mode. Reading this register also resets this bit.
WDT—Watch-Dog Timer Time-Out Indicator
If this bit is set to 1, a WDT time-out occurred. A Power-On Reset resets this pin. A STOP
Mode Recovery from a change in an input pin also resets this bit. Reading this register
resets this bit. This read must occur before clearing the WDT interrupt.
EXT—External Reset Indicator
If this bit is set to 1, a Reset initiated by the external RESET pin occurred. A Power-On
Reset or a STOP Mode Recovery from a change in an input pin resets this bit. Reading this
register resets this bit.
Reserved—Must be 0.
LVD—Low Voltage Detection Indicator
If this bit is set to 1 the current state of the supply voltage is below the low voltage detec-
tion threshold. This value is not latched but is a real-time indicator of the supply voltage
level.
PS022815-0206
Reset, STOP Mode Recovery and Low Voltage Detection
ZILOG [ ZILOG, INC. ]
