DV164136 Microchip Technology, DV164136 Datasheet - Page 82

• Manufacturer Part Number: DV164136
• Description: DEVELOPMENT KIT FOR PIC18
• Manufacturer: Microchip Technology
• Series: PIC®r
• Type: MCUr

Specifications of DV164136

• Contents: Board, Cables, CDs, PICkit™ 3 Programmer, Power Supply
• Processor To Be Evaluated: PIC18F8722, PIC18F87J11
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3.3 V, 5 V
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18F8xxx
• Kit Contents: PIC18 Exp Brd PICkit 3 Cable CD PSU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PIC18F8722, PIC18F87J11
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F87J11 FAMILY
5.3.5
The STATUS register, shown in Register 5-4, contains
the arithmetic status of the ALU. The STATUS register
can be the operand for any instruction, as with any
other register. If the STATUS register is the destination
for an instruction that affects the Z, DC, C, OV or N bits,
then the write to these five bits is disabled.
These bits are set or cleared according to the device
logic. Therefore, the result of an instruction with the
STATUS register as destination may be different than
intended. For example, CLRF STATUS will set the Z bit
but leave the other bits unchanged. The STATUS
register then reads back as ‘000u u1uu’. It is
REGISTER 5-4:
DS39778D-page 82
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) 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
recommended, therefore, 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 not affecting any Status bits, see
the instruction set summaries in Table 25-2 and
Table 25-3.
OV
Note:
The C and DC bits operate as a borrow and
digit borrow bit 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