PIC18F2331/2431/4331/4431
BNOV
Branch if Not Overflow
BNZ
Branch if Not Zero
Syntax:
[ label ] BNOV
-128 n 127
n
Syntax:
[ label ] BNZ
-128 n 127
if Zero bit is ‘0’,
n
Operands:
Operation:
Operands:
Operation:
if Overflow bit is ‘0’,
(PC) + 2 + 2n PC
(PC) + 2 + 2n PC
Status Affected:
Encoding:
None
Status Affected:
Encoding:
None
1110
0101
nnnn
nnnn
1110
0001
nnnn
nnnn
Description:
If the Overflow bit is ‘0’, then the
program will branch.
Description:
If the Zero bit is ‘0’, then the program
will branch.
The 2’s complement number, ‘2n’, 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.
The 2’s complement number, ‘2n’, 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.
Words:
Cycles:
1
Words:
Cycles:
1
1(2)
1(2)
Q Cycle Activity:
If Jump:
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to
PC
Decode
Read literal
‘n’
Process
Data
Write to PC
No
No
No
No
No
No
No
No
operation
operation
operation
operation
operation
operation
operation
operation
If No Jump:
Q1
If No Jump:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
HERE
BNOV Jump
Example:
HERE
BNZ Jump
Before Instruction
Before Instruction
PC
=
address (HERE)
PC
=
address (HERE)
After Instruction
If Overflow
PC
After Instruction
=
=
=
=
0;
If Zero
PC
If Zero
PC
=
=
=
=
0;
address (Jump)
1;
address (HERE + 2)
address (Jump)
1;
address (HERE + 2)
If Overflow
PC
DS39616D-page 294
2010 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
