PIC18F2331/2431/4331/4431
TABLE 24-1: OPCODE FIELD DESCRIPTIONS
Field
Description
a
RAM access bit:
a = 0: RAM location in Access RAM (BSR register is ignored)
a = 1: RAM bank is specified by BSR register
bbb
BSR
d
Bit address within an 8-bit file register (0 to 7).
Bank Select Register. Used to select the current RAM bank.
Destination select bit:
d = 0: store result in WREG
d = 1: store result in file register f
dest
f
Destination either the WREG register or the specified register file locations.
8-bit register file address (0x00 to 0xFF).
fs
12-bit register file address (0x000 to 0xFFF). This is the source address.
12-bit register file address (0x000 to 0xFFF). This is the destination address.
Literal field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value).
Label name.
fd
k
label
mm
The mode of the TBLPTR register for the table read and table write instructions.
Only used with table read and table write instructions:
*
No Change to register (such as TBLPTR with table reads and writes).
Post-Increment register (such as TBLPTR with table reads and writes).
Post-Decrement register (such as TBLPTR with table reads and writes).
Pre-Increment register (such as TBLPTR with table reads and writes).
*+
*-
+*
n
The relative address (2’s complement number) for relative branch instructions, or the direct address for
Call/Branch and Return instructions.
PRODH
PRODL
s
Product of Multiply High Byte.
Product of Multiply Low Byte.
Fast Call/Return Mode Select bit:
s = 0: do not update into/from Shadow registers
s = 1: certain registers loaded into/from shadow registers (Fast mode)
u
Unused or Unchanged.
WREG
x
Working register (accumulator).
Don’t care (‘0’ or ‘1’).
The assembler will generate code with x = 0. It is the recommended form of use for compatibility with all
Microchip software tools.
TBLPTR
TABLAT
TOS
21-bit Table Pointer (points to a Program Memory location).
8-bit Table Latch.
Top-of-Stack.
PC
Program Counter.
PCL
Program Counter Low Byte.
Program Counter High Byte.
Program Counter High Byte Latch.
Program Counter Upper Byte Latch.
Global Interrupt Enable bit.
Watchdog Timer.
PCH
PCLATH
PCLATU
GIE
WDT
TO
Time-out bit.
PD
Power-Down bit.
C, DC, Z, OV, N
ALU Status bits: Carry, Digit Carry, Zero, Overflow, Negative.
Optional.
[
]
)
(
Contents.
< >
Assigned to.
Register bit field.
In the set of.
italics
User-defined term (font is Courier New).
DS39616D-page 284
2010 Microchip Technology Inc.
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