PIC18F4539 Datasheet, PDF (223/322 Pages) Microchip Technology – Enhanced FLASH Microcontrollers with Single Phase Induction Motor Control Kernel

PIC18FXX39
BNC
Branch if Not Carry
Syntax:
[ label ] BNC n
Operands:
-128 ≤ n ≤ 127
Operation:
if carry bit is ‘0’
(PC) + 2 + 2n → PC
Status Affected: None
Encoding:
1110 0011 nnnn nnnn
Description:
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.
Words:
1
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Decode
Read literal
'n'
No
operation
No
operation
Q3
Process
Data
No
operation
Q4
Write to PC
No
operation
If No Jump:
Q1
Decode
Q2
Read literal
'n'
Q3
Process
Data
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:
[ label ] BNN n
Operands:
-128 ≤ n ≤ 127
Operation:
if negative bit is ‘0’
(PC) + 2 + 2n → PC
Status Affected: None
Encoding:
1110 0111 nnnn nnnn
Description:
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.
Words:
1
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Decode
Read literal
'n'
No
operation
No
operation
Q3
Process
Data
No
operation
Q4
Write to PC
No
operation
If No Jump:
Q1
Decode
Q2
Read literal
'n'
Q3
Process
Data
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)
 2002 Microchip Technology Inc.
Preliminary
DS30485A-page 221