Datasheet

PIC18CXX2
DS39026D-page 56  1999-2013 Microchip Technology Inc.
5.1 Control Registers
Several control registers are used in conjunction with
the TBLRD and TBLWT instructions. These include the:
• TBLPTR registers
• TABLAT register
• RCON register
5.1.1 RCON REGISTER
The LWRT bit specifies the operation of Table Writes to
internal memory when the V
PP voltage is applied to the
MCLR
pin. When the LWRT bit is set, the controller
continues to execute user code, but long Table Writes
are allowed (for programming internal program mem-
ory) from user mode. The LWRT bit can be cleared only
by performing either a POR or MCLR
Reset.
REGISTER 5-1: RCON REGISTER (ADDRESS: FD0h)
R/W-0 R/W-0 U-0 R/W-1 R/W-1 R/W-1 R/W-0 R/W-0
IPEN LWRT —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 (16CXXX compatibility mode)
bit 6 LWRT: Long Write Enable bit
1 = Enable TBLWT to internal program memory
0 = Disable TBLWT to internal program memory.
Note: Only cleared on a POR or MCLR
Reset.
This bit has no effect on TBLWTs to external program memory.
bit 5 Unimplemented: Read as '0'
bit 4 RI
: RESET Instruction Flag bit
1 = No RESET instruction occurred
0 = A RESET instruction occurred
bit 3 TO
: Time-out bit
1 = After power-up, CLRWDT instruction, or SLEEP instruction
0 = A WDT time-out occurred
bit 2 PD
: Power-down 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 = No Power-on Reset 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 = No Brown-out Reset or POR Reset occurred
0 = A Brown-out Reset or POR 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 reset ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown