Datasheet

TCA7408
SCPS235B NOVEMBER 2011REVISED MARCH 2013
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Register 07h Output High-Impedance
The Output High-Impedance Register determines whether pins set as output are enabled or high-impedance
When a bit in this register is set to 0, the corresponding GPIO-port output state follows register the output port
register (05h).
When a bit in this register is set to 1, the corresponding GPIO-port output is set to high-impedance.
Bit values in this register have no effect on pins defined as inputs. In turn, reads from this register reflect the
value that is in the flip-flop controlling the output selection, not the actual pin value.
BIT B7 B6 B5 B4 B3 B2 B1 B0
DESCRIPTION GPIO7 GPIO6 GPIO5 GPIO4 GPIO3 GPIO2 GPIO1 GPIO0
DEFAULT 1 1 1 1 1 1 1 1
Register 09h Input Default State
The Input Default State Register sets the default state of the GPIO-port input for generating interrupts.
When a bit in this register is set to 0, the default for the corresponding input is set to LOW
When a bit in this register is set to 1, the default for the corresponding input is set to HIGH
Bit values in this register have no effect on pins defined as outputs. In turn, reads from this register reflect the
value that is in the flip-flop controlling the default state, not the actual pin value.
BIT B7 B6 B5 B4 B3 B2 B1 B0
DESCRIPTION GPIO7 GPIO6 GPIO5 GPIO4 GPIO3 GPIO2 GPIO1 GPIO0
DEFAULT 1 1 1 1 1 1 1 1
Register 0Bh – Pull-up/-down Enable
The Pull-up/-down Enable Register enables or disables the pull-up/down resistor on the GPIO-port as defined in
the Pull-up/down Select Register (0Dh).
When a bit in this register is set to 0, the pull-up/down on the corresponding GPIO is disabled.
When a bit in this register is set to 1, the pull-up/down on the corresponding GPIO is enabled.
BIT B7 B6 B5 B4 B3 B2 B1 B0
DESCRIPTION GPIO7 GPIO6 GPIO5 GPIO4 GPIO3 GPIO2 GPIO1 GPIO0
DEFAULT 1 1 1 1 1 1 1 1
Register 0Dh – Pull-up/-down Select
The Pull-up/down Select Register allows the user to select either a pull-up or pull-down on the GPIO-port. This
register only selects the pull-up/down resistor on the GPIO-port, while the enabling/disabling is controlled by the
Pull-up/down Enable Register (0Bh).
When a bit in this register is set to 0, the pull-down on the corresponding GPIO is selected.
When a bit in this register is set to 1, the pull-up on the corresponding GPIO is selected.
BIT B7 B6 B5 B4 B3 B2 B1 B0
DESCRIPTION GPIO7 GPIO6 GPIO5 GPIO4 GPIO3 GPIO2 GPIO1 GPIO0
DEFAULT 0 0 0 0 0 0 0 0
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