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Semiconductor Group
137
Instruction Set
ADD
A, <src-byte>
Function:
Add
Description:
ADD adds the byte variable indicated to the accumulator, leaving the result in the
accumulator. The carry and auxiliary carry flags are set, respectively, if there is a
carry out of bit 7 or bit 3, and cleared otherwise. When adding unsigned integers,
the carry flag indicates an overflow occurred.
OV is set if there is a carry out of bit 6 but not out of bit 7, or a carry out of bit 7 but
not out of bit 6; otherwise OV is cleared. When adding signed integers, OV indicates
a negative number produced as the sum of two positive operands, or a positive sum
from two negative operands.
Four source operand addressing modes are allowed: register, direct, register-
indirect, or immediate.
Example:
The accumulator holds 0C3
H
(11000011
B
) and register 0 holds 0AA
H
(10101010
B
).
The instruction
ADD
A,R0
will leave 6D
H
(01101101
B
) in the accumulator with the AC flag cleared and both
the carry flag and OV set to 1.
ADD
A,Rn
Operation:
ADD
(A)
←
(A) + (Rn)
Bytes:
1
Cycles:
1
ADD
A,direct
Operation:
ADD
(A)
←
(A) + (direct)
Bytes:
2
Cycles:
1
Encoding:
0 0 1 0
1 r r r
Encoding:
0 0 1 0
0 1 0 1
direct address
*
Summary of Contents for SAB 80515 Series
Page 9: ...Semiconductor Group 9 Introduction Figure 1 2 Block Diagram ...
Page 12: ...Semiconductor Group 12 Fundamental Structure Figure 2 1 Detailed Block Diagram ...
Page 18: ...Semiconductor Group 18 Central Processing Unit Figure 3 1 Fetch Execute Sequence ...
Page 73: ...Semiconductor Group 73 On Chip Peripheral Components Figure 7 25 A D Converter Block Diagram ...
Page 83: ...Semiconductor Group 83 On Chip Peripheral Components Figure 7 33 a Timer 2 Block Diagram ...
Page 215: ...Device Specifications Semiconductor Group 215 ...
Page 217: ...Device Specifications Semiconductor Group 217 Pin Configuration P LCC 68 ...
Page 219: ...Device Specifications Semiconductor Group 219 Logic Symbol ...
Page 226: ...Device Specifications Semiconductor Group 226 Figure 1 Block Diagram ...
Page 229: ...Device Specifications Semiconductor Group 229 Figure 2 Memory Address Spaces ...
Page 239: ...Device Specifications Semiconductor Group 239 Figure 4 Block Diagram of the A D Converter ...
Page 241: ...Device Specifications Semiconductor Group 241 Figure 5 Interrupt Request Sources ...
Page 242: ...Device Specifications Semiconductor Group 242 Figure 6 Interrupt Priority Level Structure ...