MC68HC705C Motorola, MC68HC705C Datasheet - Page 157

• Manufacturer Part Number: MC68HC705C
• Description: HCMOS Microcontroller Unit
• Manufacturer: Motorola

12.4.2 Read-Modify-Write Instructions
MC68HC705C8A — Rev. 2.0
MOTOROLA
NOTE:
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.
Do not use read-modify-write operations on write-only registers.
Arithmetic shift left (same as LSL)
Arithmetic shift right
Bit clear
Bit set
Clear register
Complement (one’s complement)
Decrement
Increment
Logical shift left (same as ASL)
Logical shift right
Negate (two’s complement)
Rotate left through carry bit
Rotate right through carry bit
Test for negative or zero
1. Unlike other read-modify-write instructions, BCLR and BSET use
2. TST is an exception to the read-modify-write sequence because it
only direct addressing.
does not write a replacement value.
Table 12-2. Read-Modify-Write Instructions
Instruction Set
Instruction
Mnemonic
BCLR
BSET
TST
COM
ROR
DEC
NEG
ASR
CLR
ROL
ASL
LSR
LSL
INC
(2)
Instruction Types
(1)
(1)
Technical Data
Instruction Set
157