W48C101-01 Datasheet, PDF (1/8 Pages) Cypress Semiconductor – Spread Spectrum BX System Frequency Generator

W48C101-01
Spread Spectrum BX System Frequency Generator
Features
• Maximized EMI suppression using Cypress’s Spread
Spectrum technology
• Four copies of CPU output
• Eight copies of PCI output (Synchronous w/CPU
output)
• Two copies of 14.318-MHz IOAPIC output
• Two copies of 48-MHz USB output
• Three buffered copies of 14.318-MHz reference input
• Input is a 14.318-MHz XTAL or reference signal
• Selectable 100-MHz or 66-MHz CPU outputs
• Power management control input pins
• Test mode and output three-state capability
Key Specifications
Supply Voltages:........................................V_DDQ3 = 3.3V±5%
...............................................................................................
V_DDQ2 = 2.5V±5% or 3.3V±5%
CPU0:3 Jitter (Cycle to Cycle): ................................... 200 ps
CPU0:3 Clock Skew: .................................................. 175 ps
PCI_F, PCI1:7 Clock Skew: ........................................ 500 ps
CPU to PCI Clock Skew: ..............1.5 to 4.0 ns (CPU Leads)
Logic inputs have 250-k: pull-up resistors except SEL100/66#.
Table 1. Pin Selectable Frequency
SEL
CPU PCI
100/66# SEL1 SEL0 (MHz) (MHz) SPREAD#=0
0
0
0 HI-Z HI-Z Don’t Care
0
0
1 66.6 33.3 ±0.9% Center
0
1
0 66.6 33.3 –1% Down
0
1
1 66.6 33.3 –0.5% Down
1
0
0 X1/2 X1/6 Don’t Care
1
0
1 100 33.3 ±0.9% Center
1
1
0 100 33.3 –1% Down
1
1
1 100 33.3 –0.5% Down
Rev 1.0, November 28, 2006
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