CY28442-2
PCI_STP# Assertion
PCI_STP# Deassertion
The PCI_STP# signal is an active LOW input used for
synchronous stopping and starting the PCI outputs while the
rest of the clock generator continues to function. The set-up
time for capturing PCI_STP# going LOW is 10 ns (tSU). (See
Figure 10.) The PCIF clocks will not be affected by this pin if
their corresponding control bit in the SMBus register is set to
allow them to be free-running.
The deassertion of the PCI_STP# signal will cause all PCI and
stoppable PCIF clocks to resume running in a synchronous
manner within two PCI clock periods after PCI_STP# transi-
tions to a high level.
Tsu
PCI_STP#
PCI_F
PCI
SRC 100MHz
Figure 10. PCI_STP# Assertion Waveform
Tdrive_SRC
Tsu
PCI_STP#
PCI_F
PCI
SRC 100MHz
Figure 11. PCI_STP# Deassertion Waveform
FS_A, FS_B,FS_C
VTT_PWRGD#
PWRGD_VRM
0.2-0.3mS
Delay
Wait for
VTT_PWRGD#
Device is not affected,
VTT_PWRGD# is ignored
Sample Sels
State 2
VDD Clock Gen
Clock State
State 0
Off
State 1
State 3
On
Clock Outputs
Clock VCO
On
Off
Figure 12. VTT_PWRGD# Timing Diagram
Rev 1.0,November 21, 2006
Page 13 of 19
SPECTRALINEAR [ SPECTRALINEAR INC ]
