CY2287
100-MHz Spread Spectrum Clock Synthesizer/Driver with
USB, Hublink, and SDRAM Support
Features
• Mixed 2.5V and 3.3V Operation
• Multiple output clocks at different frequencies
— Three CPU clocks at 2.5V, up to 100 MHz
— Nine 3.3V SDRAM clocks at 100 MHz
— Eight synchronous PCI clocks at 33 MHz
— Two synchronous APIC clocks at 16.67 MHz or 33
MHz
— Two 3V66 clocks at 66 MHz
— Two USB clocks at 48 MHz
— One reference clock at 14.318 MHz
• Spread Spectrum clocking
— 31 kHz modulation frequency
— EPROM programmable percentage of spreading
— Default is –0.6%, which is recommended by Intel®
— Additional options of –0.25% and –0.4% available
• Power-down features
• I
2
C™ Interface
• Low skew and low jitter outputs
• Test Mode
• 56-pin SSOP package
Benefits
Usable with Pentium II, K6, and 6x86 Processors
Single-chip main motherboard clock generator
— High-Speed Processor Support
— Supports Two 4-Clock SDRAM DIMMs
— Support for Six PCI Slots
— Synchronous to the CPU Clock
— Hublink Support
— Universal Serial Bus Support
— Also used as an input strap to determine APIC frequency
Enables reduction of EMI
Supports mobile systems
Dynamic output control
Meets tight system timing requirements at high frequency
Enables ATE and “bed of nails” testing
Widely available, standard package enables lower cost
SSOP
Top View
REF0/SEL33 (14.318 MHz)
REF0/SEL33
V
DDREF
XTAL_IN
XTAL_OUT
V
SSREF
V
SS3V66
3V66_0
3V66_1
1
2
3
4
5
6
7
8
9
10
11
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
V
SSAPIC
APIC0
APIC1
V
DDAPIC
CPU0
V
DDCPU
CPU1
CPU2
V
SSCPU
V
SSSDRAM
SDRAM0
SDRAM1
V
DDSDRAM
SDRAM2
SDRAM3
V
SSSDRAM
SDRAM4
SDRAM5
V
DDSDRAM
SDRAM6
SDRAM7
V
SSSDRAM
SDRAM8
V
DDSDRAM
PWRDWN
SCLK
SDATA
SEL1
Logic Block Diagram
CPU [0–2] (66/100 MHz)
XTALIN
XTALOUT
14.318
MHz
OSC.
CPU
PLL
EPROM
Configurable
Logic
SDRAM [0-8] (100 MHz)
V
DD3V66
V
DDPCI
PCI0
PCI1
SEL0
SEL1
EPROM
PCI [0–7] (33MHz)
APIC [0–1] (16.67/33MHz)
3V66 [0–1] (66MHz)
SYS
PLL
PCI2
V
SSPCI
PCI3
PCI4
V
SSPCI
PCI5
PCI6
PCI7
V
DDPCI
AV
DD
AV
SS
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
PWR_DWN
USB [0–1] (48MHz)
SCLK
SDATA
SERIAL INTERFACE
CONTROL LOGIC
V
SSUSB
USB0
USB1
V
DDUSB
SEL0
Intel and Pentium are registered trademarks of Intel Corporation.
I
2
C is a trademark of Philips Corporation.
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
CY2287
•
12
13
408-943-2600
June 23, 1999
CYPRESS [ CYPRESS SEMICONDUCTOR ]
