PIC18F2220/2320/4220/4320
BZ
Branch if Zero
[ label ] BZ
CALL
Subroutine Call
Syntax:
n
Syntax:
[ label ] CALL k [,s]
Operands:
Operation:
-128 ≤ n ≤ 127
Operands:
0 ≤ k ≤ 1048575
s ∈ [0,1]
if Zero bit is ’1’
(PC) + 2 + 2n → PC
Operation:
(PC) + 4 → TOS,
k → PC<20:1>,
if s = 1
Status Affected:
Encoding:
None
1110
0000
nnnn
nnnn
(W) → WS,
(STATUS) → STATUSS,
(BSR) → BSRS
Description:
If the Zero bit is ‘1’, then the
program 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.
Status Affected:
None
Encoding:
1st word (k<7:0>)
2nd word(k<19:8>)
1110
1111
110s
k kkk
kkkk
kkkk
7
0
8
k
kkk kkkk
19
Description:
Subroutine call of entire 2 Mbyte
memory range. First, return
Words:
Cycles:
1
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 regis-
ters, WS, STATUSS and BSRS. If
‘s’ = 0, no update occurs (default).
Then, the 20-bit value ‘k’ is loaded
into PC<20:1>. CALLis a two-cycle
instruction.
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to PC
No
No
operation
No
operation
No
operation
operation
Words:
Cycles:
2
2
If No Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read literal Push PC to Read literal
HERE
BZ Jump
Example:
‘k’<7:0>,
stack
‘k’<19:8>,
Write to PC
Before Instruction
PC
=
address (HERE)
No
No
No
No
operation
operation
operation
operation
After Instruction
If Zero
=
=
=
=
1;
PC
address (Jump)
HERE
CALL THERE,FAST
Example:
If Zero
PC
0;
address (HERE+2)
Before Instruction
PC
=
address (HERE)
After Instruction
PC
=
=
=
=
address (THERE)
TOS
WS
address (HERE + 4)
W
BSR
STATUS
BSRS
STATUSS=
DS39599C-page 270
2003 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
