a) Jump Instructions
i) Unconditional Jump
The program sequence is transferred to the memory location specified by the 16-bit address without checking any condition.
- Syntax: JMP 16-bit address
- e.g. JMP 8085
ii) Conditional Jump
|
Op-code
|
Description
|
Flag status
|
|
JC
|
Jump on carry
|
CY=1
|
|
JNC
|
Jump on no carry
|
CY=0
|
|
JP
|
Jump on positive
|
S=0
|
|
JM
|
Jump on minus
|
S=1
|
|
JPE
|
Jump on even parity
|
P=1
|
|
JPO
|
Jump on odd parity
|
P=0
|
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JZ
|
Jump on zero
|
Z=1
|
|
JNZ
|
Jump on non-zero
|
Z=0
|
b) Call Instructions / Return Instructions
i) Unconditional call/return
Syntax: CALL 16-bit address
:
:
:
RET
ii) Conditional call/return
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Op-code
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Description
|
Flag status
|
|
CC/RC
|
Call/Return on carry
|
CY=1
|
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CNC/RNC
|
Call/Return on no carry
|
CY=0
|
|
CP/RP
|
Call/Return on positive
|
S=0
|
|
CM/RM
|
Call/Return on minus
|
S=1
|
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CPE/RPE
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Call/Return on even parity
|
P=1
|
|
CPO/RPO
|
Call/Return on odd parity
|
P=0
|
|
CZ/RZ
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Call/Return on zero
|
Z=1
|
|
CNZ/RNZ
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Call/Return on non-zero
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Z=0
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c) Restart Instructions
The RST instructions are equivalent to 1-byte call instructions to one of the eight memory locations on page 0. The instructions are generally used in conjunction with interrupts and inserted using external hardware. However, these can be used as software instructions in a program to transfer program execution to one of the eight locations.
|
Op-code
|
Restart Address (H)
|
|
RST 0
|
0000
|
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RST 1
|
0008
|
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RST 2
|
0010
|
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RST 3
|
0018
|
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RST 4
|
0020
|
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RST 5
|
0028
|
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RST 6
|
0030
|
|
RST 7
|
0038
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