PIC18FXX20
LFSR
Load FSR
MOVF
Move f
Syntax:
[ label ] LFSR f,k
Syntax:
[ label ] MOVF f [,d [,a]
Operands:
0 ≤ f ≤ 2
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
f → dest
N, Z
0 ≤ k ≤ 4095
Operation:
Status Affected:
Encoding:
k → FSRf
None
1110
1111
Operation:
Status Affected:
Encoding:
1110
0000
00ff
k kkk
11
kkkk
k kkk
0101
00da
ffff
ffff
7
Description:
The 12-bit literal 'k' is loaded into
the file select register pointed to
by 'f'.
2
2
Description:
The contents of register 'f' are
moved to a destination dependent
upon the status of ’d’. If 'd' is 0, the
result is placed in W. If 'd' is 1, the
result is placed back in register 'f'
(default). Location 'f' can be any-
where in the 256-byte bank. 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).
Words:
Cycles:
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read literal
Process
Write
literal 'k'
MSB to
FSRfH
'k' MSB
Data
Decode
Read literal
'k' LSB
Process
Data
Write literal
'k' to FSRfL
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
LFSR 2, 0x3AB
Example:
Q2
Q3
Q4
Write W
After Instruction
Decode
Read
Process
FSR2H
FSR2L
=
=
0x03
0xAB
register 'f'
Data
MOVF
REG, 0, 0
Example:
Before Instruction
REG
W
=
=
0x22
0xFF
After Instruction
REG
W
=
=
0x22
0x22
2003 Microchip Technology Inc.
Advance Information
DS39609A-page 283
MICROCHIP [ MICROCHIP ]
