XCHD exchanges the low-order nibble of the Accumulator (bits 3 through 0), generally representing a hexadecimal or BCD digit, with that of the internal RAM location indirectly addressed by the specified register. The high-order nibbles (bits 7-4) of each register are not affected. No flags are affected.
Encoding: 1 1 0 1 0 1 1 i
R0 contains the address 20H. The Accumulator holds the value 36H (00110110B). Internal RAM location 20H holds the value 75H (01110101B). The following instruction,
XCHD A,@R0
leaves RAM location 20H holding the value 76H (01110110B) and 35H (00110101B) in the Accumulator
Encoding: 1 1 0 1 0 1 1 i
R0 contains the address 20H. The Accumulator holds the value 36H (00110110B). Internal RAM location 20H holds the value 75H (01110101B). The following instruction,
XCHD A,@R0
leaves RAM location 20H holding the value 76H (01110110B) and 35H (00110101B) in the Accumulator
Related topics:
8051 Complement Accumulator and Bit | 8051 Set Bit | 8051 Clear Accumulator and Bit | 8051 Rotate Accumulator | 8051 Swap Nibble | 8051 Exchange Accumulator | 8051 Push and Pop | 8051 No Operation
List of topics: 8051
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