Datasheet

Table Of Contents
PIC18F2221/2321/4221/4321 FAMILY
DS39689F-page 48 © 2009 Microchip Technology Inc.
REGISTER 5-1: RCON: RESET CONTROL REGISTER
R/W-0 R/W-1
(1)
U-0 R/W-1 R-1 R-1 R/W-0
(2)
R/W-0
IPEN SBOREN
—RITO PD POR BOR
bit 7 bit 0
bit 7 IPEN: Interrupt Priority Enable bit
1 = Enable priority levels on interrupts
0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode)
bit 6 SBOREN: BOR Software Enable bit
(1)
If BOREN<1:0> = 01:
1 = BOR is enabled
0 = BOR is disabled
If BOREN<1:0> =
00, 10 or 11:
Bit is disabled and read as ‘0’.
bit 5 Unimplemented: Read as ‘0
bit 4 RI: RESET Instruction Flag bit
1 = The RESET instruction was not executed (set by firmware only)
0 = The RESET instruction was executed causing a device Reset (must be set in software after
a Brown-out Reset occurs)
bit 3 TO: Watchdog Time-out Flag bit
1 = Set by power-up, CLRWDT instruction or SLEEP instruction
0 = A WDT time-out occurred
bit 2 PD
: Power-Down Detection Flag bit
1 = Set by power-up or by the CLRWDT instruction
0 = Set by execution of the SLEEP instruction
bit 1 POR
: Power-on Reset Status bit
(2)
1 = A Power-on Reset has not occurred (set by firmware only)
0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)
bit 0 BOR
: Brown-out Reset Status bit
1 = A Brown-out Reset has not occurred (set by firmware only)
0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs)
Note 1: If SBOREN is enabled, its Reset state is1’; otherwise, it is0’.
2: The actual Reset value of POR
is determined by the type of device Reset. See the
notes following this register and Section 5.6 “Reset State of Registers” for
additional information.
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set 0’ = Bit is cleared x = Bit is unknown
Note 1: It is recommended that the POR bit be set after a Power-on Reset has been
detected so that subsequent Power-on Resets may be detected.
2: Brown-out Reset is said to have occurred when BOR
is ‘0’ and POR is ‘1’ (assuming
that POR
was set to1’ by software immediately after Power-on Reset).