FDC37B78X SMSC Corporation, FDC37B78X Datasheet - Page 128

• Manufacturer Part Number: FDC37B78X
• Description: Enhanced Super I/O Controller with ACPI Support/ Real Time Clock and Consumer IR
• Manufacturer: SMSC Corporation

When a GPIO port is programmed as an input,
reading it through the GPIO data register
latches either the inverted or non-inverted logic
value present at the GPIO pin.
GPIO port that is programmed as an input has
no effect.
HOST OPERATION
WRITE
READ
TABLE 56 - GPIO READ/WRITE BEHAVIOR
LATCHED VALUE OF GPIO
PIN
NO EFFECT
Writing to a
GPIO INPUT PORT
128
When a GPIO port is programmed as an output,
the logic value or the inverted logic value that
has been written into the GPIO data register is
output to the GPIO pin. Reading from a GPIO
port that is programmed as an output returns
the last value written to the data register.
LAST WRITE TO GPIO DATA
REGISTER
BIT PLACED IN GPIO DATA
REGISTER
GPIO OUTPUT PORT