PRELIMINARY
W250
FTG for VIA Apollo Pro-266
Table 1. Pin Selectable Frequency
(continued)
Features
Input Address
CPU,
(MHz)
78
PCI
(MHz)
Spread
Spectrum
Maximized EMI Suppression using Cypress’s Spread
Spectrum Technology
•
FS4 FS3 FS2 FS1 FS0
AGP
0
0
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
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
0
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
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
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
0
1
78
83
39
OFF
OFF
OFF
+0.5%
–0.5%
OFF
OFF
OFF
OFF
OFF
OFF
+0.5%
–0.5%
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
+0.5%
–0.5%
System frequency synthesizer for VIA Apollo Pro-266
Supports Intel® Pentium® II and Pentium® III class pro-
cessor
•
•
83
41.5
33.4
33.4
33.3
34.3
35.6
36.6
37.6
38.3
33.4
33.4
33.3
39
66.8
66.8
66.6
103
66.8
66.8
66.6
68.6
71.3
73.3
75.3
76.6
66.8
66.8
66.6
78
Four copies of CPU output
Nine copies of PCI output
One 48-MHz output for USB
One 24-MHz or 48-MHz output for SIO
Two buffered reference outputs
Two APIC output
•
•
•
•
•
•
•
•
•
•
107
110
113
115
100.2
100.2
100.0
117
Supports frequencies up to 200 MHz
2
I C™ interface for programming
Power management control inputs
Available in 48-pin SSOP
120
80
40
124
82.7
65
41.3
32.5
33.7
34.5
35.5
36.0
37.5
38.7
40
Key Specifications
130
135
67.5
69
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
138
141
70.5
72
144
150
75
155
77.5
80
160
Table 1. Pin Selectable Frequency
166
83
41.5
33.3
33.4
33.4
33.3
Input Address
CPU,
PCI
Spread
200
66.6
66.8
66.8
66.6
FS4 FS3 FS2 FS1 FS0
(MHz)
AGP
69
(MHz)
Spectrum
133.6
133.6
133.3
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
69
72
75
34.5
36
OFF
OFF
OFF
72
75
37.5
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
APIC0:1
VDD_AGP
VDD_48 MHz
FS3*/48 MHz
FS2*/24_48 MHz
GND_48 MHz
PCI_F
5
APIC1
GND_APIC
CPU_F
VDD_CPU
GND_CPU
CPU1
DIV
6
7
8
9
AGP0:2
DIV
CPU_STOP#
VDD_CPU
CPU_F
PCI1
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
PWR_DWN#
FS0:1
PCI2
CPU2
GND_PCI
PCI3
VDD_CPU
GND_CPU
CPU3
Stop
Clock
CPU1:3
PLL 1
Control
PCI4
VDD_PCI
PCI5
PCI6
PCI7
GND_PCI
PCI8
*FS1
*FS0
AGP0
VDD_AGP
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#
Control
2
SDATA
SCLK
I C
Logic
VDD_48 MHz
48MHz/FS3
Note:
1. Signals marked with ‘*’ have internal pull-up resistors.
PLL2
÷2
24_48MHz/FS2
Intel and Pentium are registered trademarks of Intel Corporation. I2C is a trademark of Philips Corporation.
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
August 4, 2000, rev. **