MC68711E20CFNE3 Datasheet, PDF (71/242 Pages) –

Instruction Set
4.5.3 Extended
In the extended addressing mode, the effective address of the argument is contained in two bytes
following the opcode byte. These are 3-byte instructions (or 4-byte instructions if a prebyte is required).
One or two bytes are needed for the opcode and two for the effective address.
4.5.4 Indexed
In the indexed addressing mode, an 8-bit unsigned offset contained in the instruction is added to the value
contained in an index register (IX or IY). The sum is the effective address. This addressing mode allows
referencing any memory location in the 64-Kbyte address space. These are 2- to 5-byte instructions,
depending on whether or not a prebyte is required.
4.5.5 Inherent
In the inherent addressing mode, all the information necessary to execute the instruction is contained in
the opcode. Operations that use only the index registers or accumulators, as well as control instructions
with no arguments, are included in this addressing mode. These are
1- or 2-byte instructions.
4.5.6 Relative
The relative addressing mode is used only for branch instructions. If the branch condition is true, an 8-bit
signed offset included in the instruction is added to the contents of the program counter to form the
effective branch address. Otherwise, control proceeds to the next instruction. These are usually 2-byte
instructions.
4.6 Instruction Set
Refer to Table 4-2, which shows all the M68HC11 instructions in all possible addressing modes. For each
instruction, the table shows the operand construction, the number of machine code bytes, and execution
time in CPU E-clock cycles.
M68HC11E Family Data Sheet, Rev. 5.1
Freescale Semiconductor
71