Microchip Technology MCP1630DM-DDBS1 Datenbogen
©
2007 Microchip Technology Inc.
DS41211D-page 87
PIC12F683
12.3.4
BROWN-OUT RESET (BOR)
The BOREN0 and BOREN1 bits in the Configuration
Word register select one of four BOR modes. Two
modes have been added to allow software or hardware
control of the BOR enable. When BOREN<1:0> =
Word register select one of four BOR modes. Two
modes have been added to allow software or hardware
control of the BOR enable. When BOREN<1:0> =
01
,
the SBOREN bit of the PCON register enables/disables
the BOR, allowing it to be controlled in software. By
selecting BOREN<1:0> =
the BOR, allowing it to be controlled in software. By
selecting BOREN<1:0> =
10
, the BOR is automatically
disabled in Sleep to conserve power and enabled on
wake-up. In this mode, the SBOREN bit is disabled.
See Register 12-1 for the Configuration Word
definition.
wake-up. In this mode, the SBOREN bit is disabled.
See Register 12-1 for the Configuration Word
definition.
A brown-out occurs when V
DD
falls below V
BOR
for
greater than parameter T
BOR
“Electrical Specifications”). The brown-out condition
will reset the device. This will occur regardless of V
will reset the device. This will occur regardless of V
DD
slew rate. A Brown-out Reset may not occur if V
DD
falls
below V
BOR
for less than parameter T
BOR
.
On any Reset (Power-on, Brown-out Reset, Watchdog
Timer, etc.), the chip will remain in Reset until V
Timer, etc.), the chip will remain in Reset until V
DD
rises
above V
BOR
(see Figure 12-3). If enabled, the
Power-up Timer will be invoked by the Reset and keep
the chip in Reset an additional 64 ms.
the chip in Reset an additional 64 ms.
If V
DD
drops below V
BOR
while the Power-up Timer is
running, the chip will go back into a Brown-out Reset
and the Power-up Timer will be re-initialized. Once V
and the Power-up Timer will be re-initialized. Once V
DD
rises above V
BOR
, the Power-up Timer will execute a
64 ms Reset.
12.3.5
BOR CALIBRATION
The PIC12F683 stores the BOR calibration values in
fuses located in the Calibration Word register (2008h).
The Calibration Word register is not erased when using
the specified bulk erase sequence in the
“PIC12F6XX/16F6XX Memory Programming Specifi-
cation” (DS41204) and thus, does not require
reprogramming.
fuses located in the Calibration Word register (2008h).
The Calibration Word register is not erased when using
the specified bulk erase sequence in the
“PIC12F6XX/16F6XX Memory Programming Specifi-
cation” (DS41204) and thus, does not require
reprogramming.
FIGURE 12-3:
BROWN-OUT SITUATIONS
Note:
The Power-up Timer is enabled by the
PWRTE bit in the Configuration Word
register.
PWRTE bit in the Configuration Word
register.
Note:
Address 2008h is beyond the user pro-
gram memory space. It belongs to the
special configuration memory space
(2000h-3FFFh), which can be accessed
only during programming. See
“PIC12F6XX/16F6XX Memory Program-
ming Specification” (DS41204) for more
information.
special configuration memory space
(2000h-3FFFh), which can be accessed
only during programming. See
“PIC12F6XX/16F6XX Memory Program-
ming Specification” (DS41204) for more
information.
64 ms
(1)
V
BOR
V
DD
Internal
Reset
V
BOR
V
DD
Internal
Reset
64 ms
(1)
< 64 ms
64 ms
(1)
V
BOR
V
DD
Internal
Reset
Note 1:
64 ms delay only if PWRTE bit is programmed to ‘
0
’.