Edge Port Flag Register (Epfr); Edge Port Flag Register - Motorola M-CORE MMC2001 Series Reference Manual

EPDx — Edge Port Data x
See the description above. These bits are not affected by hardware reset.

13.3.4 Edge Port Flag Register (EPFR)

The 16-bit read/write edge port flag register (EPFR) indicates whether the selected
edge has been detected on the port pins.
EPFR — Edge Port Flag Register
15 14 13 12
R 0 0 0 0
W
RESET:
EPFx — Edge Port Flag x
0 = Selected edge for INTx pin has not been detected.
1 = Selected edge for INTx pin has been detected.
Bits in this register are set when the programmed edge is detected on the corre-
sponding pin. A bit remains set until cleared by writing it to a one. Pin transitions do
not affect this register if the pin is configured as level sensitive (EPPARx=00). The
corresponding flag bit(s) are cleared to zero in this case. When a pin is configured as
a general-purpose output, writes to EPDR that cause the selected level or edge inter-
rupt will set the corresponding bit in EPFR. The outputs of this register drive the cor-
responding input of the interrupt controller for those bits configured as edge
detecting. These bits are cleared by hardware reset.
MOTOROLA
13-4
Freescale Semiconductor, Inc.
11 10 9 8
0 0 0 0
Figure 13-5 Edge Port Flag Register
EXTERNAL INTERRUPTS/GPIO (EDGE PORT)
For More Information On This Product,
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7 6 5 4
EPF7 EPF6 EPF5 EPF4
0 0 0 0
10007006
3 2 1 0
EPF3 EPF2 EPF1 EPF0
0 0 0 0
MMC2001
REFERENCE MANUAL