PIC18F258 MICROCHIP [Microchip Technology], PIC18F258 Datasheet - Page 288

• Manufacturer Part Number: PIC18F258
• Description: High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18FXX8
BCF
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example:
DS41159B-page 286
Q Cycle Activity:
Before Instruction
After Instruction
Decode
FLAG_REG = 0xC7
FLAG_REG = 0x47
Q1
register ’f’
Bit Clear f
[ label ] BCF
0
0
a
0
None
Bit 'b' in register 'f' is cleared. If ‘a’
is 0, the Access Bank will be
selected, overriding the BSR value.
If ‘a’ = 1, then the bank will be
selected as per the BSR value
(default).
1
1
BCF
Read
1001
Q2
f
b
[0,1]
f<b>
255
7
FLAG_REG,
bbba
Process
Data
Q3
f,b[,a]
ffff
7
register ’f’
Write
Q4
ffff
BN
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example:
Q Cycle Activity:
If Jump:
If No Jump:
Before Instruction
After Instruction
operation
Decode
Decode
PC
If Negative
If Negative
No
Q1
Q1
PC
PC
Read literal
Read literal
operation
Branch if Negative
[ label ] BN
-128
if negative bit is ’1’
(PC) + 2 + 2n
None
If the Negative bit is ’1’, 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
1(2)
HERE
1110
No
Q2
Q2
’n’
’n’
=
=
=
=
=
2002 Microchip Technology Inc.
n
address (HERE)
1;
address (Jump)
0;
address (HERE+2)
127
0110
operation
BN
Process
Process
n
Data
Data
No
Q3
Q3
PC
Jump
nnnn
Write to PC
operation
operation
Q4
No
Q4
No
nnnn