W83697HF/F
7. GENERAL PURPOSE I/O
W83697HF provides 24 input/output ports that can be individually configured to perform a simple basic
I/O function or a pre-defined alternate function. Those 24 GP I/O ports are divided into three groups,
each group contains 8 ports. The first group is configured through control registers in logical device 7,
the second group in logical device 8, and the third group in logical device 9. Users can configure each
individual port to be an input or output port by programming respective bit in selection register (CRF0: 0 =
output, 1 = input). Invert port value by setting inversion register (CRF2: 0 = non-inverse, 1 = inverse).
Port value is read/written through data register (CRF1). Table 7.1 and 7.2 gives more details on GPIO's
assignment. In addition, GPIO1 is designed to be functional even in power loss condition (VCC or VSB
is off). Figure 7.1 shows the GP I/O port's structure. Right after Power-on reset, those ports default to
perform basic input function except ports in GPIO1 which maintains its previous settings until a battery
loss condition.
Table 7.1
SELECTION BIT
0 = OUTPUT
1 = INPUT
INVERSION BIT
0 = NON INVERSE
1 = INVERSE
BASIC I/O OPERATIONS
0
0
1
1
0
1
0
1
Basic non-inverting output
Basic inverting output
Basic non-inverting input
Basic inverting input
Publication Release Date: Feb. 2002
Revision 0.70
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