CY28378 Cypress Semiconductor, CY28378 Datasheet - Page 13

• Manufacturer Part Number: CY28378
• Description: FTG for Pentium 4 and Intel 845 Series Chipset
• Manufacturer: Cypress Semiconductor

Document #: 38-07519 Rev. **
PD# – Deassertion
After the clock chip internal PLL is powered up and locked, all
outputs will be enabled within a few clock cycles of each other,
with the first to last active clock taking no more than two full
PCI clock cycles.
Table 9. PWRDWN# Functionality
PWRDWN#
1
0
REF, 14.131818
CPUC, 133MHz
CPUT, 133MHz
AGP, 66MHz
USB, 48MHz
PCI, 33MHz
PWRDWN#
Normal
Iref x2
CPUT
Figure 3. Power-down Deassertion Timing Waveforms
Normal
CPUC
Float
Tdrive_PWRDN#
<300 s, >200mV
Tstable
<1.8ms
66MHz
3V66
Low
PCI_F/PCI
3V66/2
Low
CY28378
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48MHz
48M
Low