Hardware Reference
In-Depth Information
INTCAPx Register
The interrupt capture register reports the status of the inputs as the interrupt is being
raised. This register is read-only. Readi
ng this
register cle
ars the
INTFx
register, to allow
new interrupts to be generated. When
INT A
is linked to
INT B
, both
INTCAPA
and
INTCAPB
must be read to clear the interrupt (or read the
GPIOx
registers).
INTCAPx Register
GPIO
Address
Bit
7
6
5
4
3
2
1
0
A
0x10
R
Y
Y
Y
Y
Y
Y
Y
Y
B
0x11
W
N
N
N
N
N
N
N
N
Reset
0
0
0
0
0
0
0
0
INTCAPx Bit Value
0
Input state was 0 at time of interrupt
1
Input state was 1 at time of interrupt
GPIOx Register
Reading this register provides the current input pin values, for pins configured a
s
inputs. Rea
ding th
e
GPIOx
register also clears the interrupt flags in
INTFx
. When
INT A
is linked to
INT B
, both
GPIOA
and
GPIOB
must be read to clear the interrupt (or read the
INTCAPx
registers).
Presumably, the
OLATx
register is read, for pins configured for output (the datasheet
doesn't say). Writing to the
GPIOx
register alters the
OLATx
settings in addition to
immediately affecting the outputs.
GPIOx Register
GPIO
Address
Bit
7
6
5
4
3
2
1
0
A
0x12
R
Y
Y
Y
Y
Y
Y
Y
Y
B
0x13
W
Y
Y
Y
Y
Y
Y
Y
Y
Reset
X
X
X
X
X
X
X
X
