MC68HC05K0 Datasheet, PDF (60/154 Pages) Freescale Semiconductor, Inc – HCMOS Microcontroller Unit

Technical Data
Freescale Semiconductor, Inc.
6.3 Stop Mode
The STOP instruction puts the microcontroller unit (MCU) in its lowest
power-consumption mode and has these effects on the MCU:
• Clears TOF and RTIF, the timer interrupt flags in the timer status
and control register, removing any pending timer interrupts
• Clears TOIE and RTIE, the timer interrupt enable bits in the timer
status and control register, disabling further timer interrupts
• Clears the multifunction timer counter register
• Sets the IRQE bit in the IRQ status and control register to enable
external interrupts
• Clears the I bit in the condition code register, enabling interrupts
• Stops the internal oscillator, turning off the central processor unit
(CPU) clock and the timer clock, including the computer operating
properly (COP) watchdog, and holds OSC2 at a logic 1
The STOP instruction does not affect any other registers or any
input/output (I/O) lines.
These conditions bring the MCU out of stop mode:
• An external interrupt signal on the IRQ/V_PP pin — A high-to-low
transition on the IRQ/V_PP pin loads the program counter with the
contents of locations $03FA and $03FB.
• An external interrupt signal on a port A external interrupt pin — If
the mask option for the port A external interrupt function is
selected, a low-to-high transition on a PA3–PA0 pin loads the
program counter with the contents of locations $03FA and $03FB.
• Low-voltage reset — A low-voltage detect resets the MCU and
loads the program counter with the contents of locations $03FE
and $03FF (if this mask option is selected).
• External reset — A logic 0 on the RESET pin resets the MCU and
loads the program counter with the contents of locations $03FE
and $03FF.
When the MCU exits stop mode, processing resumes after a
stabilization delay of 4064 oscillator cycles.
Technical Data
MC68HC05K0 • MC68HC05K1 — Rev. 2.0
Low-Power Modes
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