MC68HC705C8A Datasheet, PDF (155/222 Pages) Motorola, Inc – HCMOS Microcontroller Unit

12.3.8 Relative
Instruction Set
Instruction Types
Relative addressing is only for branch instructions. If the branch
condition is true, the CPU finds the effective branch destination by
adding the signed byte following the opcode to the contents of the
program counter. If the branch condition is not true, the CPU goes to the
next instruction. The offset is a signed, two’s complement byte that gives
a branching range of –128 to +127 bytes from the address of the next
location after the branch instruction.
When using the Motorola assembler, the programmer does not need to
calculate the offset, because the assembler determines the proper offset
and verifies that it is within the span of the branch.
12.4 Instruction Types
The MCU instructions fall into five categories:
• Register/memory instructions
• Read-modify-write instructions
• Jump/branch instructions
• Bit manipulation instructions
• Control instructions
MC68HC705C8A — Rev. 2.0
MOTOROLA
Instruction Set
Technical Data
155