W83627HF Datasheet, PDF (98/185 Pages) Winbond – WINBOND I/O

W83627HF/F
PRELIMINARY
8. GENERAL PURPOSE I/O
W83627HF 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 8.1 and 8.2
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 8.1 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 8.1
SELECTION
BIT
0 = OUTPUT
1 = INPUT
INVERSION BIT
0 = NON INVERSE
1 = INVERSE
BASIC I/O OPERATIONS
0
0
Basic non-inverting output
0
1
Basic inverting output
1
0
Basic non-inverting input
1
1
Basic inverting input
- 81 -
Publication Release Date: Jul 1999
Revision 0.53