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PIC18F2221_1 Datasheet, PDF (290/402 Pages) Microchip Technology – Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology | |||
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PIC18F2221/2321/4221/4321 FAMILY
BNOV
Branch if Not Overflow
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
If Jump:
Q1
Decode
No
operation
If No Jump:
Q1
Decode
BNOV n
-128 ⤠n ⤠127
If Overflow bit is â0â,
(PC) + 2 + 2n â PC
None
1110 0101 nnnn nnnn
If the Overflow bit is â0â, then the
program will branch.
The 2âs complement number â2nâ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
1
1(2)
Q2
Read literal
ânâ
No
operation
Q3
Process
Data
No
operation
Q4
Write to
PC
No
operation
Q2
Read literal
ânâ
Q3
Process
Data
Q4
No
operation
Example:
HERE
Before Instruction
PC
=
After Instruction
If Overflow =
PC =
If Overflow =
PC =
BNOV Jump
address (HERE)
0;
address (Jump)
1;
address (HERE + 2)
BNZ
Branch if Not Zero
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
If Jump:
Q1
Decode
No
operation
If No Jump:
Q1
Decode
BNZ n
-128 ⤠n ⤠127
If Zero bit is â0â,
(PC) + 2 + 2n â PC
None
1110 0001 nnnn nnnn
If the Zero bit is â0â, then the program
will branch.
The 2âs complement number â2nâ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
1
1(2)
Q2
Read literal
ânâ
No
operation
Q3
Process
Data
No
operation
Q4
Write to
PC
No
operation
Q2
Read literal
ânâ
Q3
Process
Data
Q4
No
operation
Example:
HERE
Before Instruction
PC
=
After Instruction
If Zero
=
PC
=
If Zero
=
PC
=
BNZ Jump
address (HERE)
0;
address (Jump)
1;
address (HERE + 2)
DS39689F-page 290
© 2009 Microchip Technology Inc.
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