MC68HC908MR8 Datasheet, PDF (78/372 Pages) Motorola, Inc – Microcontrollers

Central Processor Unit (CPU)
6.5 Arithmetic/Logic Unit (ALU)
The ALU performs the arithmetic and logic operations defined by the
instruction set.
Refer to the CPU08 Reference Manual, Freescale document number
CPU08RM/AD, for a description of the instructions and addressing
modes and more detail about CPU architecture.
6.6 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-consumption
standby modes.
6.6.1 Wait Mode
The WAIT instruction:
• Clears the interrupt mask (I bit) in the condition code register,
enabling interrupts. After exit from wait mode by interrupt, the I bit
remains clear. After exit by reset, the I bit is set.
• Disables the CPU clock
6.6.2 Stop Mode
The STOP instruction:
• Clears the interrupt mask (I bit) in the condition code register,
enabling external interrupts. After exit from stop mode by external
interrupt, the I bit remains clear. After exit by reset, the I bit is set.
• Disables the CPU clock
After exiting stop mode, the CPU clock begins running after the oscillator
stabilization delay.
Technical Data
78
Central Processor Unit (CPU)
MC68HC908MR8 — Rev 4.1
Freescale Semiconductor