MC68HC05P4A Datasheet, PDF (48/72 Pages) Advanced Analogic Technologies – Microcontrollers

Instruction Set
11.3.2 Read-Modify-Write Instructions
These instructions read a memory location or a register, modify its contents, and write the modified value
back to the memory location or to the register. The test for negative or zero instruction (TST) is an
exception to the read-modify-write sequence because it does not write a replacement value. Table 11-2
lists the read-modify-write instructions.
Table 11-2. Read-Modify-Write Instructions
Instruction
Arithmetic shift left
Arithmetic shift right
Clear bit in memory
Set bit in memory
Clear
Complement (one’s complement)
Decrement
Increment
Logical shift left
Logical shift right
Negate (two’s complement)
Rotate left through carry bit
Rotate right through carry bit
Test for negative or zero
Mnemonic
ASL
ASR
BCLR
BSET
CLR
COM
DEC
INC
LSL
LSR
NEG
ROL
ROR
TST
MC68HC05P4A Data Sheet, Rev. 7.1
48
Freescale Semiconductor