mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 360

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

Introduction
16.1.2 Modes of operation
The LLWU module becomes functional on entry into a low-leakage power mode. After
recovery from LLS, the LLWU is then immediately disabled. After recovery from VLLS,
the LLWU continues to detect wakeup events until the user has acknowledged the
wakeup via a write to the PMC_REGSC[ACKISO] bit.
16.1.2.1 LLS mode
The LLWU module provides up to 16 external wakeup inputs and up to 8 internal module
wakeup inputs. In addition, an LLS reset event can be initiated via assertion of the
RESET pin.
Wakeup events due to external wakeup inputs and internal module wakeup inputs result
in an interrupt flow when exiting LLS. A reset event due to RESET pin assertion results
in a reset flow when exiting LLS.
16.1.2.2 VLLS modes
The LLWU module provides up to 16 external wakeup inputs and up to 8 internal module
wakeup inputs. In addition, a VLLS reset event can be initiated via assertion of the
RESET pin. All wakeup and reset events result in VLLS exit via a reset flow.
16.1.2.3 Non-low leakage modes
The LLWU is not active in all non-low leakage modes where detection and control logic
are in a static state. The LLWU registers are accessible in non-low leakage modes and are
available for configuring and reading status when bus transactions are possible.
When the reset or wakeup pin filters are enabled, filter operation begins immediately. If a
low leakage mode is entered within 5 LPO clock cycles of an active edge, the edge event
will be detected by the LLWU. For RESET pin filtering, this means there is no restart to
the minimum LPO cycle duration as the filtering transitions from a non-low leakage filter
(implemented in the RCM) to the LLWU filter.
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The LLWU interrupt must not be masked by the interrupt
controller to avoid a scenario where the system does not fully
exit stop mode on an LLS recovery.
MCF51JF128 Reference Manual, Rev. 2, 03/2011
Preliminary
NOTE
Freescale Semiconductor, Inc.