MC68HC912BD32 Datasheet, PDF (190/292 Pages) Freescale Semiconductor, Inc – Advance Information

Freescale Semiconductor, Inc.
Byteflight™ Module
Low Power Modes
In addition to normal mode, the Serial Bus Interface module has three
modes with reduced power consumption: Sleep, Soft Reset and Power
Save mode. In Sleep and Soft Reset mode, power consumption is
reduced by stopping all clocks except those to access the register. In
Power Save mode, all clocks are stopped and no power is consumed
(except leakage current).
The WAI and STOP instruction put the MCU in low power consumption
stand-by modes. Table 39 summarizes the combinations of Byteflight™
and CPU modes. A particular combination of modes is entered for the
given settings of the bits SSWAI, SLPAK, and SFTRES. For all modes,
an Byteflight™ wake-up interrupt can occur only if SLPAK=WAKEIE=1.
While the CPU is in Wait mode, the Byteflight™ can be operated in
normal mode and generate interrupts. Registers can still be accessed
via background debug mode.
Table 39 Byteflight™ vs. CPU operating modes
Byteflight™
Mode
Power Save
STOP
SSWAI = X⁽¹⁾
SLPAK = X
SFTRES = X
Sleep
Soft Reset
Normal
1. ‘X’ means don’t care.
CPU Mode
WAIT
SSWAI = 1
SLPAK = X
SFTRES = X
SSWAI = 0
SLPAK = 1
SFTRES = 0
SSWAI = 0
SLPAK = 0
SFTRES = 1
SSWAI = 0
SLPAK = 0
SFTRES = 0
RUN
SSWAI = X
SLPAK = 1
SFTRES = 0
SSWAI = X
SLPAK = 0
SFTRES = 1
SSWAI = X
SLPAK = 0
SFTRES = 0
MC68HC912BD32 Rev 1.0
Byteflight™ Module
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