dp8344b National Semiconductor Corporation, dp8344b Datasheet - Page 142

• Manufacturer Part Number: dp8344b
• Description: Biphase Communications Processor?bcp
• Manufacturer: National Semiconductor Corporation

6 0 Reference Section
JMP Unconditional Relative Jump
Syntax
JMP n
JMP Rs
Affected Flags
None
Description
Unconditionally transfers control to the instruction at the
memory address calculated by adding the contents of the
Program Counter to either the immediate value n or the con-
tents of the source register Rs (both sign extended to 16
bits) Since the immediate value n and the contents of Rs
are 8-bit two’s complement displacements the uncondition-
al relative jump’s range is from
the Program Counter Note that the Program Counter initial-
ly contains the memory address of the next instruction fol-
lowing the jump
Example
Transfer control to the instruction labeled ‘‘Init Xmit’’
which is within
Instruction Format
JMP n
JMP Rs
T-states
JMP n
JMP Rs
Bus Timing
JMP n
JMP Rs
Operation
JMP n
PC
JMP Rs
PC
1
15
1
15
JMP Init Xmit
a
a
1
1
n(sign extended)
Rs(sign extended)
0
0
Opcode
0
0
a
1
1
Opcode
127
Figure 6-2
Figure 6-4
immediate
register
3
4
1
0
b
go initialize Transmitter
1
0
x
128 words relative to the PC
x
1
1
PC
PC
1
7
a
127 to
0
(Continued)
0
b
4
n
128 relative to
Rs
0
0
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