Edge Port Module (EPORT)
MCF52110 ColdFire® Integrated Microcontroller Reference Manual, Rev. 1
15-2
Freescale Semiconductor
Preliminary
15.2
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 8, “Power Management”.
shows EPORT-module operation in
low-power modes and describes how this module may exit each mode.
NOTE
The control register (CR) 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.
15.3
Interrupt/GPIO Pin Descriptions
All EPORT pins default to general-purpose input pins at reset. The pin value is synchronized to the rising
edge of CLKOUT 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 CLKOUT. 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.
15.4
Memory Map/Register Definition
This subsection describes the memory map and register structure. Refer to
the EPORT memory map. The EPORT has an IPSBAR offset of 0x13_0000.
Table 15-1. 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 CR
Doze
Normal
Any IRQ
n
interrupt at or above level in CR
Stop
Level-sensing only
Any IRQ
n
interrupt set for level-sensing at or
above level in CR. See note below.