W254B
133-MHz Spread Spectrum FTG for
Mobile Pentium® III Platforms
APIC, 48-MHz, 3V66, PCI Outputs
Features
Cycle-to-Cycle Jitter: ...................................................500 ps
• Maximized EMI suppression using Cypress’s Spread
Spectrum technology (–0.5% and ±0.5%)
CPU Output Skew: ......................................................150 ps
3V66 Output Skew: .....................................................175 ps
APIC, SDRAM Output Skew: ......................................250 ps
PCI Output Skew:........................................................500 ps
VDDQ3 (REF, PCI, 3V66, 48 MHz, SDRAM):.........3.3V±5%
VDDQ2 (CPU, APIC):....... 2.5V±5%in Selectable Frequency
Table 1. Pin Selectable Frequency
• Single chip system FTG for Mobile Intel® Platforms
• Two CPU outputs
• Seven copies of PCI clock (one Free Running)
• Seven SDRAM clock (one DCLK for Memory Hub)
• Two copies of 48-MHz clock (non-spread spectrum) op-
timized for USB reference input and video DOT clock
• Three 3V66 Hublink/AGP outputs
• One VCH clock (48-MHz non-SSC or 66.67-MHz SSC)
• One APIC outputs
Input
Address
Output Frequencies
FS1 FS0 CPU SDRAM 48MHz PCI APIC REF 3V66
• One buffered reference output
0
0
1
1
0
1
0
1
66
100
100
133
100
• Supports frequencies up to 133 MHz
• SMBus interface for programming
• Power management control inputs
48
MHz
33
MHz
14.318 66
MHz MHz
100
133
133
Key Specifications
CPU, SDRAM Outputs Cycle-to-Cycle Jitter:.............. 250 ps
Block Diagram
Pin Configuration
VDD_REF
REF
PLL Ref Freq
X1
X2
XTAL
OSC
REF
APIC
VDD_APIC
VDD_CPU
CPU
CPU_F
GND_CPU
GND_SDRAM
SDRAM0
SDRAM1
VDD_SDRAM
SDRAM2
SDRAM3
GND_SDRAM
SDRAM4
SDRAM5
DCLK
VDD_SDRAM
CPU_STP#
VDD_REF
X1
1
2
3
4
5
6
7
8
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
Divider
Network
PLL 1
VDD_CPU
CPU
Stop
Clock
X2
GND_REF
GND_PCI
PCI_F/FS0^
PCI1/FS1^
PCI2
Control
CPU_F
CPU_STP#
VDD_APIC
APIC
VDD_SDRAM
DCLK
VDD_PCI
PCI3
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
SDRAM0:5
PCI4
PCI5
PCI6
VDD_PCI
PCI_F/FS0
PWR_DWN#
PCI_STP#
Stop
Clock
Control
VDD_3V66
3V66_0
3V66_1
3V66_AGP
GND_3V66
VCH_CLK
GND_48
USB
PCI1/FS1
PCI2:6
VDD_3V66
3V66_0:1
PCI_STP#
PWR_DWN#
SCLK
SDATA
VDD_CORE
3V66_AGP
DOT
VDD_48
GND_CORE
VDD_48
PLL2
USB (48MHz)
DOT (48MHz)
Note:
SDATA
SCLK
SMBus
Logic
VCH_CLK
1. Internal pull-down or pull-up resistors present on inputs
marked with * or ^ respectively. Design should not rely solely
on internal pull-up or pull-down resistor to set I/O pins HIGH
or LOW respectively.
Intel and Pentium are registered trademarks of Intel Corporation.
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
Document #: 38-07233 Rev. *A
Revised December 22, 2002