Microchip Technology MCP9800DM-DL2 Data Sheet

Page of 98
PIC10F200/202/204/206
DS40001239E-page 48
 
 2004-2013 Microchip Technology Inc.
9.7
Time-out Sequence, Power-down 
and Wake-up from Sleep Status 
Bits (TO, PD, GPWUF, CWUF)
The TO, PD, GPWUF and CWUF bits in the STATUS
register can be tested to determine if a Reset condition
has been caused by a power-up condition, a MCLR,
Watchdog Timer (WDT) Reset, wake-up on comparator
change or wake-up on pin change.
TABLE 9-5:
TO, PD, GPWUF, CWUF STATUS AFTER RESET
9.8
Reset on Brown-out
A Brown-out Reset is a condition where device power
(V
DD
) dips below its minimum value, but not to zero,
and then recovers. The device should be reset in the
event of a brown-out.
To reset PIC10F200/202/204/206 devices when a
Brown-out Reset occurs, external brown-out protection
circuits may be built, as shown in Figure 9-7 and
Figure 9-8.
FIGURE 9-7:
BROWN-OUT 
PROTECTION CIRCUIT 1 
FIGURE 9-8:
BROWN-OUT 
PROTECTION CIRCUIT 2 
CWUF
GPWUF
TO
PD
Reset Caused By
0
0
0
0
WDT wake-up from Sleep
0
0
0
u
WDT time-out (not from Sleep)
0
0
1
0
MCLR wake-up from Sleep
0
0
1
1
Power-up
0
0
u
u
MCLR not during Sleep
0
1
1
0
Wake-up from Sleep on pin change
1
0
1
0
Wake-up from Sleep on comparator change
Legend: u = unchanged, x = unknown, – = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1:
The TO, PD, GPWUF and CWUF bits maintain their status (u) until a Reset occurs. A low-pulse on the 
MCLR input does not change the TO, PD, GPWUF or CWUF Status bits.
Note 1:
This circuit will activate Reset when V
DD
 goes 
below Vz + 0.7V (where Vz = Zener voltage).
2:
Pin must be confirmed as MCLR.
33k
10k
40k
(1)
V
DD
MCLR
(2)
PIC10F20X
V
DD
Q1
Note 1:
This brown-out circuit is less expensive, 
although less accurate. Transistor Q1 turns 
off when V
DD
 is below a certain level such 
that:
2:
Pin must be confirmed as MCLR.
V
DD
 •
R1
R1 + R2
= 0.7V
R2
40k
(1)
V
DD
MCLR
(2)
PIC10F20X
R1
Q1
V
DD