Datasheet

Application Information
13−5
SLLS535E − April 2008 TUSB6250
13.4.3 Special Note About Pullup and Pulldown Resistors for ATA/ATAPI Signals
The TUSB6250 provides internal 200-µA pullup and/or pulldown resistors to most ATA/ATAPI bus signals,
which can be used during power-on sequencing or active modes to avoid bus floating. To ensure compliance
with the ATA/ATAPI specification, it is recommended to implement pullup and pulldown resistors at the board
level with the value defined by the ATA/ATAPI-5 specification:
IORDY 1-kΩ pullup resistor should be implemented on the ATA/ATAPI host connector (TUSB6250
side).
DMARQ 5.6-kΩ pulldown resistor should be implemented on ATA/ATAPI host connector (TUSB6250
side).
INTRQ 10-kΩ pulldown resistor should be implemented on the ATA/ATAPI host connector (TUSB6250
side).
13.4.4 Series Termination Resistors Required for Ultra DMA Operation
Series termination resistors are required at both the host and the device for operation in any of the ultra-DMA
modes. See page 13 of the ATA/ATAPI-5 specification for detailed information.