cl-pd6833 Cirrus Logic, Inc., cl-pd6833 Datasheet - Page 147

• Manufacturer Part Number: cl-pd6833
• Description: Pci-to-cardbus Host Adapter
• Manufacturer: Cirrus Logic, Inc.

CL-PD6833
PCI-to-CardBus Host Adapter
11.7.5
Bits 3:0 — GPIO[4:1] Output Control
Bits 7:4 — Reserved
11.7.6
Bits 3:0 — GPIO[4:1] Input Control
Bits 7:4 — GPIO[4:1] Pull-up Enable
June 1998
Pull-up Enable
Register Name: GPIO Output Control
I/O Index: 2Fh Extended Index: 18h
Memory Offset: 918h
Register Name: GPIO Input Control
I/O Index: 2Fh Extended Index: 19h
Memory Offset: 919h
GPIO4
R/W:0
R/W:0
Bit 7
Bit 7
When these bits are ‘0’, the corresponding GPIO pin is put into the high-impedance state. Setting
these bits causes the corresponding GPIO Output Data bit to be driven onto the corresponding
GPIO pin. If the corresponding GPIO Input Control bit is low, the output drives both active high and
active low. If the corresponding GPIO Input Control bit is high, the output is open-drain and drives
low only.
When these bits are set to ‘0’, the corresponding inputs are disabled and read back ‘1’s. This is
used to prevent floating inputs from drawing excessive power. When these bits are set, the data
read from the GPIO Input Data register reflects the value on the corresponding pin. If enabled, a
floating input can cause excessive power consumption, and can cause the other inputs to operate
incorrectly. If the corresponding GPIO Output Control bit is set, the pin is an output, regardless of
the state of the GPIO Input Control bit.
GPIO Output Control
GPIO Input Control
0
1
Pull-up Enable
ADVANCE DATA BOOK v0.3
GPIO3
R/W:0
R/W:0
Bit 6
Bit 6
GPIO pin tristate or open-collector per register 918h and 919h.
GPIO pin pull-up resistor to ‘+5V’ pin’s supply, except when outputting ‘0’.
Reserved
Pull-up Enable
GPIO2
R/W:0
R/W:0
Bit 5
Bit 5
Pull-up Enable
GPIO1
R/W:0
R/W:0
Bit 4
Bit 4
GPIO4 Output
GPIO4 Input
Control
Control
R/W:0
R/W:0
Bit 3
Bit 3
GPIO3 Output
GPIO3 Input
Control
Control
R/W:0
R/W:0
Bit 2
Bit 2
Register Compatibility Type: ext.
Register Compatibility Type: ext.
EXTENSION REGISTERS
GPIO2 Output
GPIO2 Input
Control
Control
R/W:0
R/W:0
Bit 1
Bit 1
Register Per: chip
Register Per: chip
GPIO1 Output
GPIO1 Input
Control
Control
R/W:0
R/W:0
Bit 0
Bit 0
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