Datasheet
  71M6543F/71M6543G Data Sheet 
v2    115 
Name  Location 
Rst 
Wk
Dir  Description 
VSTAT[2:0] 
SFR F9[2:0] 
–  –  R 
This word describes the source of power and the status of the VDD. 
VSTAT[2:0] 
Description 
000 
System Power OK. V3P3A>3.0v. Analog modules are functional and 
accurate.  [V3AOK,V3OK]=11 
001 
System Power Low. 2.8v<V3P3A<3.0v. Analog modules not accurate. 
Switch over to battery power is imminent. [V3AOK,V3OK]=01 
010 
Battery power and VDD OK. VDD>2.25v. Full digital functionality. 
[V3AOK,V3OK]=00, [VDDOK,VDDgt2]=11 
011 
Battery power and VDD>2.0. Flash writes are inhibited. If the 
TRIMVDD[5] fuse is blown, PLL_FAST is cleared. 
[V3AOK,V3OK]=00, [VDDOK,VDDgt2]=01 
101 
Battery power and VDD<2.0. When VSTAT=101, processor is nearly 
out of voltage. Processor failure is imminent. 
[V3AOK,V3OK]=00, [VDDOK,VDDgt2]=00 
WAKE_ARM 
28B2[5]  0  –  R/W 
Arms the WAKE timer and loads it with WAKE_TMR[7:0]. When SLEEP or LCD mode 
is asserted by the MPU, the WAKE timer becomes active. 
WAKE_TMR 
2880[7:0] 
0 
– 
R/W 
Timer duration is WAKE_TMR+1 seconds. 
WD_RST 
28B4[7]  0  0  W 
Reset the WD timer. The WD is reset when a 1 is written to this bit. Writing a one 
clears and restarts the watch dog timer. 
WF_DIO4 
28B1[2]  0  –  R 
DIO4 wake flag bit. If DIO4 is configured to wake the part, this bit is set whenever the 
de-bounced version of DIO4 rises. It is held in reset if DI04 is not configured for 
wakeup.  
WF_DIO52 
28B1[1]  0  –  R 
DIO52 wake flag bit. If DIO52 is configured to wake the part, this bit is set whenever the 
de-bounced version of DIO52 rises. It is held in reset if DI052 is not configured for wakeup.  
WF_DIO55 
28B1[0]  0  –  R 
DIO55 wake flag bit. If DIO55 is configured to wake the part, this bit is set whenever the 
de-bounced version of DIO55 rises. It is held in reset if DI055 is not configured for wakeup.  
WF_TMR 
28B1[5] 
0 
– 
R 
Indicates that the wake timer caused the part to wake up.  
WF_PB 
28B1[3] 
0 
– 
R 
Indicates that the PB caused the part to wake.  
WF_RX 
28B1[4] 
0 
– 
R 
Indicates that RX caused the part to wake.  
WF_CSTART  
WF_RST 
WF_RSTBIT 
WF_OVF 
WF_ERST 
WF_BADVDD 
28B0[7] 
28B0[6] 
28B0[5] 
28B0[4] 
28B0[3] 
28B0[2] 
0 
1 
0 
0 
0 
0 
–  R 
Indicates that the Reset pin, Reset bit, ERST pin, Watchdog timer, the cold start detector, 
or bad VBAT caused the part to reset.  










