gc80c520a CORERIVER Semiconductor, gc80c520a Datasheet - Page 94

• Manufacturer Part Number: gc80c520a
• Description: Midas1.0 Family Mask Rom/eprom/romless 8-bit Turbo Microcontrollers
• Manufacturer: CORERIVER Semiconductor

ADDC
ADDC A, Rn
ADDC A, direct
Description:
Operation:
Operation:
Encoding:
Encoding:
Function:
Example:
A, <src-byte>
Cycles:
Cycles:
Bytes:
Bytes:
Add with Carry
ADDC simultaneously adds the byte variable indicated, the carry flag and the
Accumulator contents, leaving the result in the Accumulator. The carry and
auxiliary–carry flags are set, respectively, if there is a carry-out from 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.
The Accumulator holds 0C3h (11000011b) and
(10101010b) with the carry flag set. The instruction,
ADDC A, R0
will leave 6Eh (01101110b) in the Accumulator with AC cleared and both the
carry flag and OV set to 1.
1
1
ADDC
(A)
2
2
ADDC
(A)
0
0
← (A) + (C) + (Rn)
← (A) + (C) + (Rn)
Preliminary
0
0
1
1
1
1
1
0 1 0 1
r
Page 94 of 187
r
r
direct address
register 0 holds 0AAh
Instruction Set