August 27, 1998
GENERAL RELEASE SPECIFICATION
6.1
STOP MODE
The STOP instruction puts the MCU in a mode with the lowest power consumption
and has the following affect on the MCU:
•
Turns off the CPU clock and all internal clocks by stopping the internal
oscillator. The stopped clocks turn off the COP watchdog, the Core
Timer, the programmable Timer, the analog subsystem and the SM-Bus
Interface.
•
Removes any pending Core Timer interrupts by clearing the Core Timer
interrupt flags (CTOF, RTIF) in the Core Timer status and control register
(CTSCR).
•
•
Disables any further Core Timer interrupts by clearing the Core Timer
interrupt enable bits (CTOFE, RTIE) in the CTSCR.
Removes any pending programmable Timer interrupts by clearing the
timer interrupt flags (ICF, OCF and TOF) in the timer status register
(TSR).
•
•
Disables any further programmable Timer interrupts by clearing the
timer interrupt enable bits (ICIE, OCIE and TOIE) in the timer control
register (TCR).
Enables external interrupts via the IRQ/V pin by setting the IRQE bit in
PP
the IRQ status and control register (ISCR). Enables interrupts in general
by clearing the I bit in the condition code register.
The STOP instruction does not affect any other bits, registers or I/O lines.
The following conditions bring the MCU out of stop mode:
•
An external interrupt signal on the IRQ/V
pin — A high to low
PP
transition on the IRQ/V
pin loads the program counter with the
PP
contents of locations $1FFA and $1FFB.
•
External reset — A logic zero on the RESET pin resets the MCU and
loads the program counter with the contents of locations $1FFE and
$1FFF.
When the MCU exits stop mode, processing resumes after a stabilization delay of
4064 oscillator cycles.
If an external interrupt brings the MCU out of stop mode after an active edge
occurred on the PC3/TCAP during the stop mode, the ICF flag becomes set. An
external interrupt also latches the value of the timer registers into the input cap-
ture registers.
If an external reset brings the MCU out of the stop mode after an active edge
occurred on the PC3/TCAP pin during the stop mode, the ICF flag does not
become set. An external reset has no effect on the input capture registers.
MC68HC05SB7
REV 2.1
LOW POWER MODES
MOTOROLA
6-3
FREESCALE [ Freescale ]
