PIC18F6390 Datasheet, PDF (306/412 Pages) Microchip Technology – 64/80-Pin Flash Microcontrollers with LCD Driver and nanoWatt Technology

PIC18F6390/6490/8390/8490
BCF
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Q1
Decode
Bit Clear f
BCF f, b {,a}
0 ≤ f ≤ 255
0≤b≤7
a ∈ [0,1]
0 → f<b>
None
1001 bbba ffff ffff
Bit ‘b’ in register ‘f’ is cleared.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
1
1
Q2
Read
register ‘f’
Q3
Process
Data
Q4
Write
register ‘f’
Example:
BCF
Before Instruction
FLAG_REG = C7h
After Instruction
FLAG_REG = 47h
FLAG_REG, 7, 0
BN
Branch if Negative
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
If Jump:
Q1
Decode
No
operation
If No Jump:
Q1
Decode
BN n
-128 ≤ n ≤ 127
if Negative bit is ‘1’
(PC) + 2 + 2n → PC
None
1110 0110 nnnn nnnn
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)
Q2
Read literal
‘n’
No
operation
Q3
Process
Data
No
operation
Q4
Write to PC
No
operation
Q2
Read literal
‘n’
Q3
Process
Data
Q4
No
operation
Example:
HERE
Before Instruction
PC
=
After Instruction
If Negative =
PC
=
If Negative =
PC
=
BN Jump
address (HERE)
1;
address (Jump)
0;
address (HERE + 2)
DS39629B-page 304
Preliminary
 2004 Microchip Technology Inc.