
138
PIN NO.
/QFP
DEFAULT
FUNC.
ALT.
FUNC.1
ALT.
FUNC.2
ALT.
FUNC.3
DATA
REGISTER
DATA
REGISTER
BIT NO.
REGISTER
OFFSET
(HEX)
100
101
102
103
104
105
106
107
108
109
110
4
5
7
8
N/A
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
Reserved
Note1
Reserved
Note1
GPIO
Reserved
Note1
Reserved
IRQ3
IRQ4
IRQ5
IRQ6
IRQ7
IRQ9
IRQ10
IRQ11
IRQ12
IRQ14
IRQ15
GPIO
GPIO
-
GPIO
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
GP7
51
GP8
4A
Note 1: These pins default to a reserved function and must be programmed to their GPIO function
immediately following power-up.
Note 2: The GPIO Data and Configuration Registers are located in PME block at the offset shown
from the RUNTIME REGISTERS BLOCK address.
GPIO Control
Each GPIO port has an 8-bit control register that controls the behavior of the pin. These registers are
defined in the “Runtime Registers” section of this specification. Excluding GP25, GP26 and GP27
which are input only, each GPIO port may be configured as either an input or an output. If the pin is
configured as an output, it can be programmed as open-drain or push-pull. Inputs and outputs can be
configured as non-inverting or inverting. Bit[0] of each GPIO Configuration Register determines the
port direction, bit[1] determines the signal polarity, and bit[7] determines the output driver type select.
The GPIO configuration register Output Type select bit[7] applies to GPIO functions and the nIO_SMI
Alternate functions. GP25, GP26 and GP27 are general purpose inputs. These pins have no output
capability.
The Polarity Bit (bit 1) of the GPIO control registers control the GPIO pin when the pin is configured
for the GPIO function and when the pin is configured for the alternate function for all pins, with the
exception of the DDRC function on GP43 and the either edge triggered interrupts. The basic GPIO
configuration options are summarized in Table 50.
Table 50 - GPIO Configuration Summary
DIRECTION
BIT
BIT
B0
B1
0
0
0
1
1
0
1
1
SELECTED
FUNCTION
POLARITY
DESCRIPTION
GPIO
Pin is a non-inverted output
Pin is an inverted output
Pin is a non-inverted input
Pin is an inverted input