MMC2001
PROGRAMMING REFERENCE
MOTOROLA
REFERENCE MANUAL
C-29
EPDDx — Edge Port Data Direction x
0 =
Pin INTx is an input.
1 =
Pin INTx is an output.
These bits are cleared by reset.
C.7.3 Edge Port Data Register (EPDR)
The edge port data register (EPDR) is a 16-bit register. Writes to EPDR are stored in
an internal latch, and if any pin of the port is configured as an output, the data stored
for that bit is driven onto the pin. Reads of this register return the value sensed on the
pins for those pins configured as inputs, or the data stored in the register for the pins
configured as outputs.
X = Unaffected by reset
Figure C-30 Edge Port Data Register
EPD[7:0] — Edge Port Data Bits 7:0
See the above description. These bits are not affected by hardware reset.
C.7.4 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.
Figure C-31 Edge Port Flag Register
EPFx — Edge Port Flag Bit 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 (EPPARn=00), and 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 which cause the selected level or edge
EPDR — Edge Port Data Register
10007004
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
0
0
0
0
0
0
0
0
EPD7
EPD6
EPD5
EPD4
EPD3
EPD2
EPD1
EPD0
W
RESET:
X
X
X
X
X
X
X
X
EPFR — Edge Port Flag Register
10007006
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
0
0
0
0
0
0
0
0
EPF7 EPF6 EPF5 EPF4 EPF3 EPF2 EPF1 EPF0
W
RESET:
0
0
0
0
0
0
0
0
Freescale Semiconductor,
I
Freescale Semiconductor, Inc.
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