PIC17C7XX Datasheet, PDF (205/328 Pages) Microchip Technology – High-Performance 8-Bit CMOS EPROM Microcontrollers with 10-bit A/D

PIC17C7XX
CALL
Subroutine Call
Syntax:
[ label ] CALL k
Operands:
0 ≤ k ≤ 8191
Operation:
PC+ 1→ TOS, k → PC<12:0>,
k<12:8> → PCLATH<4:0>;
PC<15:13> → PCLATH<7:5>
Status Affected: None
Encoding:
111k kkkk kkkk kkkk
Description:
Subroutine call within 8K page. First,
return address (PC+1) is pushed onto
the stack. The 13-bit value is loaded
into PC bits<12:0>. Then the
upper-eight bits of the PC are copied
into PCLATH. CALL is a two-cycle
instruction.
See LCALL for calls outside 8K memory
space.
Words:
1
Cycles:
2
Q Cycle Activity:
Q1
Q2
Decode
Read literal
'k'<7:0>,
Push PC to
stack
No
operation
No
operation
Q3
Process
Data
No
operation
Q4
Write to PC
No
operation
Example:
HERE
CALL THERE
Before Instruction
PC = Address(HERE)
After Instruction
PC = Address(THERE)
TOS = Address (HERE + 1)
CLRF
Clear f
Syntax:
[label] CLRF f,s
Operands:
0 ≤ f ≤ 255
Operation:
00h → f, s ∈ [0,1]
00h → dest
Status Affected: None
Encoding:
0010 100s ffff ffff
Description:
Clears the contents of the specified reg-
ister(s).
s = 0: Data memory location 'f' and
WREG are cleared.
s = 1: Data memory location 'f' is
cleared.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q2
Read
register 'f'
Q3
Process
Data
Q4
Write
register 'f'
and if
specified
WREG
Example:
CLRF
Before Instruction
FLAG_REG =
WREG
=
After Instruction
FLAG_REG =
WREG
=
FLAG_REG, 1
0x5A
0x01
0x00
0x01
© 1998 Microchip Technology Inc.
DS30289A-page 205