CY28401 Cypress Semiconductor, CY28401 Datasheet - Page 8

• Manufacturer Part Number: CY28401
• Description: 100-MHz Differential Buffer for PCI Express and SATA
• Manufacturer: Cypress Semiconductor

Document #: 38-07592 Rev. **
Output Enable Clarification
The OE function may be implemented in two ways, via writing
a ‘0’ to SMBus register bit corresponding to output of interest
or by asserting an OE input pin low. In both methods, if SMBus
registered bit has been written low or the OE pin is low or both,
the output of interest will be three-stated. (The assertion and
deassertion of this signal is absolutely asynchronous.)
Table 6. OE Functionality
OE (Pin)#
DIFC(Free Running
DIFT(Free Running
DIFC(Free Running
DIFC(Free Running
DIFT(Free Running
DIFT(Free Running
DIFC (Stoppable)
DIFT (Stoppable)
DIFC (Stoppable)
DIFC (Stoppable)
DIFT (Stoppable)
DIFT (Stoppable)
SRC_STOP#
SRC_STOP#
SRC_STOP#
1
1
0
0
PWRDWN#
PWRDWN#
PWRDWN#
Figure 7. SRC_STOP# =Three-state, PWRDWN# = Three-state
Figure 5. SRC_STOP# =Driven, PWRDWN# = Three-state
Figure 6. SRC_STOP# =Three-state, PWRDWN# = Driven
OE (SMBus Bit)
1
0
1
0
Three-state
Three-state
Three-state
Normal
DIFT
1mS
1mS
1mS
Normal
DIFC
Low
Low
Low
CY28401
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