Datasheet

Miscellaneous and GPIO Configuration Registers
9−6
SLLS535E − April 2008TUSB6250
9.6 PUPDFUNC: Pullup/Pulldown Configuration Register for Functional Pins (XDATA
at F08E)
The PUPDFUNC register allows the MCU to select/deselect and enable/disable the internal pullup or pulldown
resistor connection on certain functional pins.
76543210
PDATPDD7 PDVBUS PDATPDAT PDDMARQ POFFIORDY PUSLIORDY POFFINTRQ PUSLINTRQ
R/W R/W R/W R/W R/W R/W R/W R/W
BIT
NAME RESET FUNCTION
0 PUSLINTRQ 0 INTRQ pin pullup/pulldown resistor selection configuration by the MCU.
 If the MCU sets this bit to 1, the pullup resistor is selected and the pulldown resistor is
deselected.
 If the MCU clears this bit to 0, the pulldown resistor is selected and the pullup resistor is
deselected.
The power-up default is the pulldown resistor enabled and the pullup resistor disabled for the
INTRQ pin.
1 POFFINTRQ 0 INTRQ pin pullup/pulldown resistor power-down configuration by the MCU.
 If the MCU sets this bit to 1, both the pullup and pulldown resistors are disabled.
 If the MCU clears this bit to 0, either the pullup or the pulldown resistor is enabled for the
INTRQ pin, with the selection controlled by the PUSLINTRQ bit.
2 PUSLIORDY 0 IORDY pin pullup/pulldown resistor selection configuration by the MCU.
 If the MCU sets this bit to 1, the pullup resistor is selected and the pulldown resistor is
deselected.
 If the MCU clears this bit to 0, the pulldown resistor is selected and the pullup resistor is
deselected.
The power-up default is the pulldown enabled and the pullup disabled for the IORDY pin. The
MCU must enable the pullup on the IORDY pin during normal operation.
3 POFFIORDY 0 IORDY pin pullup/pulldown resistor power-down configuration by the MCU.
 If the MCU sets this bit to 1, both the pullup and pulldown resistors are disabled.
 If the MCU clears this bit to 0, either the pullup or the pulldown resistor is enabled for the
IORDY pin, with the selection controlled by the PUSLIORDY bit.
4 PDDMARQ 0 DMARQ pin pulldown resistor enable/disable configuration by the MCU.
 If the MCU sets this bit to 1, the pulldown resistor is disconnected from the pin.
 If the MCU clears this bit to 0, the pulldown resistor is connected to the pin.
5 PDATPDAT 0 ATAPI data bus (DD15−DD8, DD6−DD0) pin pulldown resistor enable/disable configuration by
the MCU. The DD7 pin has its own pulldown resistor control (PDATPDD7), as described in bit 7
of this register.
 If the MCU sets this bit to 1, the pulldown resistors are disconnected from the 16-bit data bus
(except DD7).
 If the MCU clears this bit to 0, the pulldown resistors are connected to the 16-bit data bus
(except DD7).
6 PDVBUS 0 VBUS pin pulldown resistor enable/disable configuration by the MCU. Before getting into
suspend, the firmware checsk the VBUS status and turns off the pulldown resistor if VBUS is
active.
 If the MCU sets this bit to 1, the pulldown resistor is disconnected from the pin.
 If the MCU clears this bit to 0, the pulldown resistor is connected to the pin.
7 PDATPDD7 0 ATAPI data bus DD7 pin pulldown resistor enable/disable configuration by the MCU. The
pulldown resistor control for the other ATA/ATAPI data bus pins is defined in bit 5 (PDATPDAT)
of this register.
 If the MCU sets this bit to 1, the pulldown resistor is disconnected from the DD7 pin.
 If the MCU clears this bit to 0, the pulldown resistor is connected to the DD7 pin.
The power-up default is the pulldown resistor enabled for the DD7 pin.