LPC47M112_07 SMSC [SMSC Corporation], LPC47M112_07 Datasheet - Page 117

• Manufacturer Part Number: LPC47M112_07
• Description: Enhanced Super I/O Controller with LPC Interface
• Manufacturer: SMSC [SMSC Corporation]

Enhanced Super I/O Controller with LPC Interface
Datasheet
22.1.1 GPIO OPERATION
The operation of the GPIO ports is illustrated in Figure 4. Note: Figure 7 is for illustration purposes only and is not
intended to suggest specific implementation details.
Note: When the following functions are selected, the associated GPIO pins have bi-directional functionality: P12,
P16, P17 and game port x-axis and y-axis inputs (J1X, J1Y, J2X, J2Y).
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. Writing to a GPIO port that is programmed as an input has no
effect (Table 57).
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 (Table 57). When the GPIO is programmed as an output, the pin is excluded
from the PME and SMI logic.
SMSC DS – LPC47M112
GPx_nIOW
GPx_nIOR
HOST
SELECTED
FUNCTION
SD-bit
GPIO
Data Register
Transparent
D-TYPE
D
Q
GPIO
Bit-n
Q
D
DIRECTION
GPIO INPUT PORT
Table 54 - GPIO Configuration Summary
FIGURE 7 -GPIO FUNCTION ILLUSTRATION
BIT
B0
Table 55 - GPIO Read/Write Behavior
0
0
1
1
DATASHEET
0
1
POLARITY
BIT
Page 117
B1
0
1
0
1
Pin is a non-inverted output.
Pin is an inverted output.
Pin is a non-inverted input.
Pin is an inverted input.
GPIO
Configuration
Register bit-1
(Polarity)
DESCRIPTION
GPIO OUTPUT PORT
GPIO
Configuration
Register bit-0
(Input/Output)
GPIO
PIN
Rev. 02-16-07