dp8344b National Semiconductor Corporation, dp8344b Datasheet - Page 153

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

Figure 6-1
6 0 Reference Section
SHR Shift Right
Syntax
SHR Rsd b
Affected Flags
N Z C
Description
Shifts the contents of the register Rsd b bits to the right and
places the result back into that register Zeros are shifted in
from the left (i e from the MSB) The value b may specify
from 0 to 7 bit shifts The Carry flag contains the last bit
shifted out
Example
Right justify the Address Stack Pointer from the Internal
Stack Pointer register ISP
Instruction Format
T-states
2
Bus Timing
Operation
1
15
MOVE ISP R20
SHR
1
0
R20 4
Opcode
0
1
0
0
register
right justify ASP
Load ASP from ISP
0
R30
7
b
(Continued)
4
Rsd
TL F 9336 – 15
0
153
Figure 6-1
SUB Subtract Immediate
Syntax
SUB n rsd
Affected Flags
N Z C V
Description
Subtracts the immediate value n from the register rsd and
places the result back into the register rsd Note that only
the active registers R0 – R15 may be specified for rsd The
value of n is limited to 8 bits (signed range
complement format
Example
Subtract the constant 3 from register 10
Instruction Format
T-states
2
Bus Timing
Operation
rsd
b
0
15
128) Negative numbers are represented using the two’s
SUB 3 R10
Opcode
b
0
n
x
1
0
rsd
11
immediate limited register
R10
b
3
n
x
R10
3
a
rsd
127 to
0