Atmel 8051 - Page 33

The 8051 Instruction Set
Atmel 8051 Microcontrollers Hardware Manual 1-32
4316B–8051–02/04
1.14.8 CLR A
1.14.9 CLR bit
Function: Clear Accumulator
Description: CLR A clears the Accumulator (all bits set to 0). No flags are affected
Example: The Accumulator contains 5CH (01011100B). The following instruction,CLR Aleaves the Accumulator set to 00H
(00000000B).
Bytes: 1
Cycles: 1
Encoding: 11100100
Operation: CLR
(A) ← 0
Function: Clear bit
Description: CLR bit clears the indicated bit (reset to 0). No other flags are affected. CLR can operate on the carry flag or any
directly addressable bit.
Example: Port 1 has previously been written with 5DH (01011101B). The following instruction,CLR P1.2 leaves the port set
to 59H (01011001B).
CLR C
Bytes: 1
Cycles: 1
Encoding: 11000011
Operation: CLR
(C) ← 0
CLR bit
Bytes: 2
Cycles: 1
Encoding: 11000010 bit address
Operation: CLR
(bit) ← 0