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Edge Port Module (EPORT)
18-2
Freescale Semiconductor
18.2
Low-Power Mode Operation
This section describes the operation of the EPORT module in low-power modes. For more information on
low-power modes, see
Chapter 9, “Power Management”.
shows EPORT-module operation in
low-power modes and describes how this module may exit each mode.
NOTE
The wakeup control register (WCR) in the system control module specifies
the interrupt level at or above what is needed to bring the device out of a
low-power mode.
In wait and doze modes, the EPORT module continues to operate as it does in run mode. It may be
configured to exit the low-power modes by generating an interrupt request on a selected edge or a low level
on an external pin. In stop mode, no clocks are available to perform the edge-detect function. Only the
level-detect logic is active (if configured) to allow any low level on the external interrupt pin to generate
an interrupt (if enabled) to exit stop mode.
NOTE
In stop mode, the input pin synchronizer is bypassed for the level-detect
logic because no clocks are available.
18.3
Signal Descriptions
All EPORT pins default to general-purpose input pins at reset. The pin value is synchronized to the rising
edge of FB_CLK when read from the EPORT pin data register (EPPDR). The values used in the edge/level
detect logic are also synchronized to the rising edge of FB_CLK. These pins use Schmitt-triggered input
buffers with built-in hysteresis designed to decrease the probability of generating false, edge-triggered
interrupts for slow rising and falling input signals.
When a pin is configured as an output, it is driven to a state whose level is determined by the corresponding
bit in the EPORT data register (EPDR). All bits in the EPDR are set at reset.
18.4
Memory Map/Register Definition
This subsection describes the memory map and register structure. Refer to
the EPORT memory map.
Table 18-1. Edge Port Module Operation in Low-Power Modes
Low-power Mode
EPORT Operation
Mode Exit
Wait
Normal
Any IRQ
n
interrupt at or above level in WCR
Doze
Normal
Any IRQ
n
interrupt at or above level in WCR
Stop
Level-sensing only
Any IRQ
n
interrupt set for level-sensing at or
above level in WCR. See note below.
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...