
PIC18FXX39
DS30485A-page 50
Preliminary
2002 Microchip Technology Inc.
4.14
RCON Register
The Reset Control (RCON) register contains flag bits
that allow differentiation between the sources of a
device RESET. These flags include the TO, PD, POR,
BOR and RI bits. This register is readable and writable.
For PIC18FXX39 devices, the IPEN bit must always be
set (= 1) for the ProMPT kernel to function correctly.
discussion.
REGISTER 4-3:
RCON REGISTER
Note 1: If the BOREN configuration bit is set
(Brown-out Reset enabled), the BOR bit is
‘1’ on a Power-on Reset. After a Brown-
out Reset has occurred, the BOR bit will
be cleared, and must be set by firmware to
indicate the occurrence of the next
Brown-out Reset.
2: 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.
R/W-0
U-0
R/W-1
R-1
R/W-0
IPEN
—
—RI
TO
PD
POR
BOR
bit 7
bit 0
bit 7
IPEN: Interrupt Priority Enable bit
Always maintain this bit set for proper operation of ProMPT kernel.
bit 6-5
Unimplemented: Read as '0'
bit 4
RI: RESET Instruction Flag bit
1
= The RESET instruction was not executed
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
= After power-up, CLRWDT instruction, or SLEEP instruction
0
= A WDT time-out occurred
bit 2
PD: Power-down Detection Flag bit
1
= After power-up or by the CLRWDT instruction
0
= By execution of the SLEEP instruction
bit 1
POR: Power-on Reset Status bit
1
= A Power-on Reset has not occurred
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
0
= A Brown-out Reset occurred
(must be set in software after a Brown-out Reset occurs)
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