3
PRELIMINARY
W250-03
FTG for VIA Apollo Pro-266
Table 1. Pin Selectable Frequency (continued)
Features
Input Address
CPU,
(MHz)
PCI
(MHz)
Spread
Spectrum
• Maximized EMI Suppression using Cypress’s Spread
Spectrum Technology
• System frequency synthesizer for VIA Apollo Pro-266
• Supports Intel® Pentium® II and Pentium® III class pro-
cessor
• Three copies of CPU output
• Nine copies of PCI output
FS4 FS3 FS2 FS1 FS0
AGP
80.0
75.0
72.5
70.0
68.0
65.0
62.0
66.6
66.6
78.7
66.6
66.8
66.8
76.7
66.8
66.8
66.8
73.3
66.8
70.0
60.0
56.7
78.0
66.6
66.6
75.0
66.6
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
160.0
150.0
145.0
140.0
136.0
130.0
124.0
66.6
40.0
37.5
36.3
35.0
34.0
32.5
31.0
33.3
33.3
39.3
33.3
33.4
33.4
38.3
33.4
33.4
33.4
36.7
33.4
35.0
30.0
28.3
39.0
33.3
33.3
37.5
33.3
OFF
OFF
OFF
OFF
OFF
• One 48-MHz output for USB
OFF
• One 24-MHz or 48-MHz output for SIO
• Two buffered reference outputs
• Three copies of APIC output
• Supports frequencies up to 200 MHz
• SMBus interface for programming
• Power management control inputs
• Available in 48-pin SSOP
OFF
OFF
100.0
118.0
133.3
66.8
OFF
OFF
OFF
+0.25%
+0.25%
OFF
100.2
115.0
133.6
66.8
Key Specifications
CPU Cycle-to-Cycle Jitter:................................................ 250 ps
CPU to CPU Output Skew:............................................... 175 ps
PCI Cycle to Cycle Jitter:.................................................. 500 ps
PCI to PCI Output Skew:.................................................. 500 ps
+0.25%
+0.5%
+0.5%
OFF
100.2
110.0
133.6
105.0
90.0
+0.5%
OFF
Table 1. Pin Selectable Frequency
Input Address
OFF
CPU,
PCI
Spread
FS4 FS3 FS2 FS1 FS0
(MHz)
AGP
66.6
63.3
60.0
56.7
83.0
(MHz)
Spectrum
85.0
OFF
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
1
1
0
0
1
0
1
0
200.0
190.0
180.0
170.0
166.0
33.3
31.7
30.0
28.3
41.5
OFF
OFF
OFF
OFF
OFF
78.0
OFF
66.6
-0.5%
-0.5%
OFF
100.0
75.0
133.3
-0.5%
Pin Configuration[1]
Block Diagram
VDD_REF
REF0
VDD_REF
GND_REF
X1
48
REF0
1
REF1/FS4
X1
X2
XTAL
OSC
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
REF1/FS4*
VDD_APIC
APIC0
2
3
VDD_APIC
PLL Ref Freq
X2
4
APIC0:2
VDD_AGP
VDD_48 MHz
FS3*/48 MHz
FS2*/24_48 MHz
GND_48 MHz
PCI_F
5
APIC1
DIV
DIV
6
GND_APIC
APIC2
7
AGP0:2
8
VDD_CPU
GND_CPU
CPU1
CPU_STOP#
VDD_CPU
9
PCI1
PCI2
GND_PCI
PCI3
PCI4
VDD_PCI
PCI5
PCI6
PCI7
GND_PCI
PCI8
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
PWR_DWN#
FS0:1
CPU2
VDD_CPU
GND_CPU
CPU3
Stop
Clock
CPU1:3
PLL 1
Control
VDD_PCI
PCI_F
CPU_STOP#*
PCI_STOP#*
PWR_DWN#*
VDD_CORE
GND_CORE
SDATA
SCLK
AGP2
AGP1
GND_AGP
÷2,3,4
PCI1:8
Stop
Clock
PCI_STOP#
*FS1
*FS0
AGP0
VDD_AGP
Control
SDATA
SCLK
SMBus
Logic
VDD_48 MHz
48MHz/FS3
Note:
1. Signals marked with ‘*’ have internal pull-up resistors.
PLL2
÷2
24_48MHz/FS2
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Cypress Semiconductor Corporation
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Document #: 38-07254 Rev. *A
Revised December 14, 2002