Datasheet

MSCAN
Low Power Options
MC9S12DP256 — Revision 1.1
MSCAN
Low Power Options
If the MSCAN is disabled (CANE=0), the MSCAN clocks are stopped for
power savings.
If the MSCAN is enabled (CANE=1), the MSCAN has two additional
modes with reduced power consumption, compared to normal mode:
Sleep and Power Down Mode. In Sleep Mode power consumption is
reduced by stopping all clocks except those to access the registers from
the CPU side. In Power Down Mode, all clocks are stopped and no
power is consumed.
Table 94 summarizes the combinations of MSCAN and CPU modes. A
particular combination of modes is entered by the given settings on the
CSWAI and SLPRQ/SLPAK bits.
For all modes, an MSCAN wake-up interrupt can only occur if the
MSCAN is in Sleep Mode (SLPRQ=1 and SLPAK=1), wake-up
functionality is enabled (WUPE=1) and the wake-up interrupt is enabled
(WUPIE=1).
Table 94 CPU vs. MSCAN Operating Modes
CPU Mode MSCAN Mode
Normal Power Down Sleep (CANE=0)
RUN
CSWAI = X
(1)
SLPRQ = 0
SLPAK = 0
CSWAI = X
SLPRQ = 1
SLPAK = 1
CSWAI = X
SLPRQ = X
SLPAK = X
WAIT
CSWAI = 1
SLPRQ = X
SLPAK = X
CSWAI = 0
SLPRQ = 1
SLPAK = 1
CSWAI = X
SLPRQ = X
SLPAK = X
STOP
CSWAI = X
SLPRQ = 0
SLPAK = 0
CSWAI = X
SLPRQ = X
SLPAK = X
CSWAI = X
SLPRQ = 1
SLPAK = 1
CSWAI = X
SLPRQ = X
SLPAK = X
1. ‘X’ means don’t care.
Freescale Semiconductor, I
Freescale Semiconductor, Inc.
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