AC162078 Microchip Technology, AC162078 Datasheet - Page 64

• Manufacturer Part Number: AC162078
• Description: HEADER INTRFC MPLAB ICD2 18F1330
• Manufacturer: Microchip Technology

Specifications of AC162078

• Accessory Type: Transition Header
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: ICD2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Not applicable / Not applicable

PIC18F1230/1330
6.3.5
The STATUS register, shown in Register 6-2, contains
the arithmetic status of the ALU. As with any other SFR,
it can be the operand for any instruction.
If the STATUS register is the destination for an instruc-
tion that affects the Z, DC, C, OV or N bits, the results
of the instruction are not written; instead, the STATUS
register is updated according to the instruction
performed. Therefore, the result of an instruction with
the STATUS register as its destination may be different
than intended. As an example, CLRF STATUS will set
the Z bit and leave the remaining Status bits
unchanged (‘000u u1uu’).
REGISTER 6-2:
DS39758D-page 64
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7-5
bit 4
bit 3
bit 2
bit 1
bit 0
Note 1:
U-0
—
2:
For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second
operand. For rotate (RRF, RLF) instructions, this bit is loaded with either bit 4 or bit 3 of the source register.
For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second
operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low-order bit of the
source register.
STATUS REGISTER
Unimplemented: Read as ‘0’
N: Negative bit
This bit is used for signed arithmetic (2’s complement). It indicates whether the result was
negative (ALU MSB = 1).
1 = Result was negative
0 = Result was positive
OV: Overflow bit
This bit is used for signed arithmetic (2’s complement). It indicates an overflow of the 7-bit
magnitude which causes the sign bit (bit 7 of the result) to change state.
1 = Overflow occurred for signed arithmetic (in this arithmetic operation)
0 = No overflow occurred
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
DC: Digit Carry/borrow bit
For ADDWF, ADDLW, SUBLW and SUBWF instructions:
1 = A carry-out from the 4th low-order bit of the result occurred
0 = No carry-out from the 4th low-order bit of the result
C: Carry/borrow bit
For ADDWF, ADDLW, SUBLW and SUBWF instructions:
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
U-0
—
STATUS REGISTER
W = Writable bit
‘1’ = Bit is set
(2)
U-0
—
(1)
R/W-x
N
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
R/W-x
It is recommended that only BCF, BSF, SWAPF, MOVFF
and MOVWF instructions are used to alter the STATUS
register because these instructions do not affect the Z,
C, DC, OV or N bits in the STATUS register.
For other instructions that do not affect Status bits, see
the instruction set summaries in Table 22-2 and
Table 22-3.
OV
Note:
The C and DC bits operate as the borrow
and digit borrow bits, respectively, in
subtraction.
R/W-x
Z
 2009 Microchip Technology Inc.
x = Bit is unknown
R/W-x
DC
(1)
R/W-x
C
(2)
bit 0