PIC18F2455_07 Datasheet, PDF (319/430 Pages) Microchip Technology – 28/40/44-Pin, High Performance, Enhanced Flash, USB Microcontrollers with nanoWatt Technology

PIC18F2455/2550/4455/4550
BNC
Branch if Not Carry
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
BNC n
-128 ≤ n ≤ 127
if Carry bit is ‘0’
(PC) + 2 + 2n → PC
None
1110 0011 nnnn nnnn
If the Carry 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.
1
Cycles:
Q Cycle Activity:
If Jump:
Q1
Decode
No
operation
If No Jump:
Q1
Decode
1(2)
Q2
Read literal
‘n’
No
operation
Q2
Read literal
‘n’
Q3
Process
Data
No
operation
Q3
Process
Data
Q4
Write to PC
No
operation
Q4
No
operation
Example:
HERE
Before Instruction
PC
=
After Instruction
If Carry
=
PC
=
If Carry
=
PC
=
BNC Jump
address (HERE)
0;
address (Jump)
1;
address (HERE + 2)
BNN
Branch if Not Negative
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
BNN n
-128 ≤ n ≤ 127
if Negative bit is ‘0’
(PC) + 2 + 2n → PC
None
1110 0111 nnnn nnnn
If the Negative 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.
1
Cycles:
Q Cycle Activity:
If Jump:
Q1
Decode
No
operation
If No Jump:
Q1
Decode
1(2)
Q2
Read literal
‘n’
No
operation
Q2
Read literal
‘n’
Q3
Process
Data
No
operation
Q3
Process
Data
Q4
Write to PC
No
operation
Q4
No
operation
Example:
HERE
Before Instruction
PC
=
After Instruction
If Negative =
PC
=
If Negative =
PC
=
BNN Jump
address (HERE)
0;
address (Jump)
1;
address (HERE + 2)
© 2007 Microchip Technology Inc.
Preliminary
DS39632D-page 317