Datasheet

 2013 Microchip Technology Inc. DS22331A-page 69
MCP19111
For example, CLRF STATUS will clear the upper three
bits and set the Z bit. This leaves the STATUS register
as ‘000u u1uu’ (where u = unchanged).
Therefore, it is recommended that only BCF, BSF,
SWAPF and MOVWF instructions are used to alter the
STATUS register, because these instructions do not
affect any Status bits. For other instructions not
affecting any Status bits, see the Section 29.0
“Instruction Set Summary”.
11.2.1 SPECIAL FUNCTION REGISTERS
The Special Function Registers are registers used by
the CPU and peripheral functions for controlling the
desired operation of the device (see Table 11-1). These
registers are static RAM.
The special registers can be classified into two sets:
core and peripheral. The Special Function Registers
associated with the microcontroller core are described
in this section. Those related to the operation of the
peripheral features are described in the section of that
peripheral feature.
Note 1: The C and DC bits operate as Borrow
and Digit Borrow out bits, respectively, in
subtraction.
REGISTER 11-1: STATUS: STATUS REGISTER
R/W-0 R/W-0 R/W-0 R-1 R-1 R/W-x R/W-x R/W-x
IRP RP1 RP0 TO
PD ZDC
(1)
C
(1)
bit 7 bit 0
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
bit 7 IRP: Register Bank Select bit (used for Indirect addressing)
1 = Reserved
0 = Bank 0, 1, 2, 3 (00h - FFh)
bit 6-5 RP<1:0>: Register Bank Select bits (used for Direct addressing)
00 = Bank 0 (00h - 7Fh)
01 = Bank 1 (80h - FFh)
10 = Bank 2 (100h - 17Fh)
11 = Bank 3 (180h - 1FFh)
bit 4 TO
: Time-out bit
1 = After power-up, CLRWDT instruction or SLEEP instruction
0 = A WDT time-out occurred
bit 3 PD
: Power-down bit
1 = After power-up or by the CLRWDT instruction
0 = By execution of the SLEEP instruction
bit 2 Z: Zero bit
1 = The result of an arithmetic or logic operation is zero
0 = The result of an arithmetic or logic operation is not zero
bit 1 DC: Digit Carry/Digit Borrow
bit
(1)
(ADDWF, ADDLW, SUBLW, SUBWF instructions)
1 = A carry-out from the 4
th
low-order bit of the result occurred
0 = No carry-out from the 4
th
low-order bit of the result
bit 0 C: Carry/Borrow
bit
(1)
(ADDWF, ADDLW, SUBLW, SUBWF instructions)
(1)
1 = A carry-out from the Most Significant bit of the result occurred
0 = No carry-out from the Most Significant bit of the result occurred
Note 1: For Borrow
, the polarity is reversed. A subtraction is executed by adding the two’s complement of the
second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high-order or low-order
bit of the source register.