Datasheet

 2000 Microchip Technology Inc. Preliminary DS40197B-page 43
PIC16HV540
8.0 INSTRUCTION SET SUMMARY
Each PIC16HV540 instruction is a 12-bit word divided
into an OPCODE, which specifies the instruction type,
and one or more operands which further specify the
operation of the instruction. The PIC16HV540 instruc-
tion set summary in Table 8-2 groups the instructions
into byte-oriented, bit-oriented, and literal and control
operations. Table 8-1 shows the opcode field descrip-
tions.
For byte-oriented instructions, ’f’ represents a file reg-
ister designator and ’d’ represents a destination desig-
nator. The file register designator is used to specify
which one of the 32 file registers is to be used by the
instruction.
The destination designator specifies where the result of
the operation is to be placed. If ’d’ is ’0’, the result is
placed in the W register. If ’d’ is ’1’, the result is placed
in the file register specified in the instruction.
For bit-oriented instructions, ’b’ represents a bit field
designator which selects the number of the bit affected
by the operation, while ’f’ represents the number of the
file in which the bit is located.
For literal and control operations, ’k’ represents an
8 or 9-bit constant or literal value.
TABLE 8-1: OPCODE FIELD
DESCRIPTIONS
All instructions are executed within one single instruc-
tion cycle, unless a conditional test is true or the pro-
gram counter is changed as a result of an instruction.
In this case, the execution takes two instruction cycles.
One instruction cycle consists of four oscillator periods.
Thus, for an oscillator frequency of 4 MHz, the normal
instruction execution time is 1 µs. If a conditional test is
true or the program counter is changed as a result of an
instruction, the instruction execution time is 2 µs.
Figure 8-1 shows the three general formats that the
instructions can have. All examples in the figure use the
following format to represent a hexadecimal number:
0xhhh
where ’h’ signifies a hexadecimal digit.
FIGURE 8-1: GENERAL FORMAT FOR
INSTRUCTIONS
Field Description
f
Register file address (0x00 to 0x7F)
W
Working register (accumulator)
b
Bit address within an 8-bit file register
k
Literal field, constant data or label
x
Don’t care location (= 0 or 1)
The assembler will generate code with x = 0.
It is the recommended form of use for com-
patibility with all Microchip software tools.
d
Destination select;
d = 0 (store result in W)
d = 1 (store result in file register ’f’)
Default is d = 1
label
Label name
TOS
Top of Stack
PC
Program Counter
WDT
Watchdog Timer Counter
TO
Time-Out bit
PD
Power-Down bit
dest Destination, either the W register or the
specified register file location
[ ] Options
( ) Contents
→ Assigned to
< > Register bit field
∈ In the set of
i
talics User defined term (font is courier)
Byte-oriented file register operations
11 6 5 4 0
d = 0 for destination W
OPCODE d f (FILE #)
d = 1 for destination f
f = 5-bit file register address
Bit-oriented file register operations
11 8 7 5 4 0
OPCODE b (BIT #) f (FILE #)
b = 3-bit bit address
f = 5-bit file register address
Literal and control operations (except GOTO)
11 8 7 0
OPCODE k (literal)
k = 8-bit immediate value
Literal and control operations - GOTO instruction
11 9 8 0
OPCODE k (literal)
k = 9-bit immediate value