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13.3 Edge Port Programming Model
The edge port programming model consists of the following registers:
• The edge port pin assignment register (EPPAR) controls the function of each pin
individually.
• The edge port data direction register (EPDDR) controls the direction of each one
of the pins individually.
• The edge port data register (EPDR) holds the data to be driven to the pins.
• The edge port flag register (EPFR) latches the edge event for each one of the
pins individually.
Access the edge port registers with halfword accesses.
Address
10007000
10007002
10007004
10007006
13.3.1 Edge Port Pin Assignment Register (EPPAR)
The 16-bit read/write edge port pin assignment register (EPPAR) configures each of
the interrupt pins as either level-sensitive or edge-triggered. Rising, falling, or both
edges can be selected as the active edge. Requests are always generated out of this
block but may be masked within the interrupt controller module. The functionality of
this register is independent of the programmed pin direction.
EPPAR — Edge Port Pin Assignment Register
15
14
13
12
R
EPPA7
EPPA6
W
RESET:
0
0
0
0
Figure 13-2 Edge Port Pin Assignment Register
EPPAx — Edge Port Pin Assignment Select Field x
Pins configured as level-sensitive are inverted so that a logic low on the external pin
represents a valid interrupt request. Level-sensitive interrupt inputs are not latched.
To guarantee that a level-sensitive interrupt request is acknowledged, the interrupt
source must keep the signal asserted until acknowledged by software.
Pins configured as edge-sensitive interrupts are latched and need not remain
asserted for interrupt generation. When the pin is programmed to use the edge
detecting circuit, its state is monitored regardless of its configuration as input or out-
put.
MOTOROLA
13-2
Freescale Semiconductor, Inc.
Table 13-1 GPIO Edge Port Address Map
Use
Edge Port Pin Assignment Register (EPPAR)
Edge Port Data Direction Register (EPDDR)
Edge Port Data Register (EPDR)
Edge Port Flag Register (EPFR)
11
10
9
8
EPPA5
EPPA4
0
0
0
0
EXTERNAL INTERRUPTS/GPIO (EDGE PORT)
For More Information On This Product,
Go to: www.freescale.com
Access
Supervisor Only
Supervisor Only
Supervisor Only
Supervisor Only
7
6
5
4
EPPA3
EPPA2
0
0
0
0
10007000
3
2
1
0
EPPA1
EPPA0
0
0
0
0
MMC2001
REFERENCE MANUAL
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