W83977EG Datasheet, PDF (76/142 Pages) Winbond – WINBOND ISA I/O

W83977EF-AW/W83977EG-AW
9. GENERAL PURPOSE I/O
W83977EF/EG provides 14 Input/Output ports that can be individually configured to perform a simple
basic I/O function or a pre-defined alternate function. Those 14 GP I/O ports are divided into three
groups, the first group contains 8 ports, and the second group contains only 6 ports. Each port in first
group corresponds to a configuration register in logical device 7, and the second group in logical
device 8. Users can select those I/O ports functions by independently programming those
configuration registers. Figure 8.1, 8.2, and 8.3 respectively show the GP I/O port's structure of logical
device 7 and 8. Right after Power-on reset, those ports default to perform basic I/O functions.
Figure 9.1
-74-