PIC18F4539 Datasheet, PDF (228/322 Pages) Microchip Technology – Enhanced FLASH Microcontrollers with Single Phase Induction Motor Control Kernel

PIC18FXX39
BZ
Branch if Zero
Syntax:
[ label ] BZ n
Operands:
-128 ≤ n ≤ 127
Operation:
if Zero bit is ‘1’
(PC) + 2 + 2n → PC
Status Affected: None
Encoding:
1110 0000 nnnn nnnn
Description:
If the Zero bit is ‘1’, then the pro-
gram 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.
Words:
1
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Decode
Read literal
'n'
No
operation
No
operation
Q3
Process
Data
No
operation
Q4
Write to PC
No
operation
If No Jump:
Q1
Decode
Q2
Read literal
'n'
Q3
Process
Data
Q4
No
operation
Example:
HERE
Before Instruction
PC
=
After Instruction
If Zero
=
PC
=
If Zero
=
PC
=
BZ Jump
address (HERE)
1;
address (Jump)
0;
address (HERE+2)
CALL
Subroutine Call
Syntax:
[ label ] CALL k [,s]
Operands:
0 ≤ k ≤ 1048575
s ∈ [0,1]
Operation:
(PC) + 4 → TOS,
k → PC<20:1>,
if s = 1
(W) → WS,
(STATUS) → STATUSS,
(BSR) → BSRS
Status Affected: None
Encoding:
1st word (k<7:0>) 1110
2nd word(k<19:8>) ¹¹¹¹
110s k₇kkk
k₁₉kkk kkkk
kkkk₀
kkkk₈
Description:
Subroutine call of entire 2 Mbyte
memory range. First, return
address (PC+ 4) is pushed onto the
return stack. If ‘s’ = 1, the W,
STATUS and BSR registers are
also pushed into their respective
shadow registers, WS, STATUSS
and BSRS. If 's' = 0, no update
occurs (default). Then, the 20-bit
value ‘k’ is loaded into PC<20:1>.
CALL is a two-cycle instruction.
Words:
2
Cycles:
2
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
Read literal
'k'<7:0>,
No
operation
Push PC to
stack
No
operation
Read literal
’k’<19:8>,
Write to PC
No
operation
Example:
HERE
CALL THERE,1
Before Instruction
PC
= address (HERE)
After Instruction
PC
=
TOS
=
WS
=
BSRS =
STATUSS=
address (THERE)
address (HERE + 4)
W
BSR
STATUS
DS30485A-page 226
Preliminary
 2002 Microchip Technology Inc.