PIC18F1220_07 Datasheet, PDF (208/308 Pages) Microchip Technology – 18/20/28-Pin High-Performance, Enhanced Flash Microcontrollers with 10-bit A/D and nanoWatt Technology

PIC18F1220/1320
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
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.
Words:
1
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Decode
No
operation
If No Jump:
Read literal
‘n’
No
operation
Process
Data
No
operation
Write to PC
No
operation
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
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:
Operands:
Operation:
Status Affected:
[ label ] CALL k [,s]
0 ≤ k ≤ 1048575
s ∈ [0,1]
(PC) + 4 → TOS,
k → PC<20:1>,
if s = 1
(W) → WS,
(Status) → STATUSS,
(BSR) → BSRS
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
Decode
Read literal
‘k’<7:0>,
No
operation
No
operation
Q3
Push PC to
stack
No
operation
Q4
Read literal
‘k’<19:8>,
Write to PC
No
operation
Example:
HERE
CALL THERE, FAST
Before Instruction
PC
= address (HERE)
After Instruction
PC
=
TOS
=
WS
=
BSRS =
STATUSS =
address (THERE)
address (HERE + 4)
W
BSR
Status
DS39605F-page 206
© 2007 Microchip Technology Inc.