APPROVED PRODUCT
C9812
Low EMI Clock Generator for Intel 810E Chipset Systems
Pin Description
PIN No.
Pin Name PWR I/O TYPE
Description
1
SEL2/REF
VDD I/O
3.3V 14.318 MHz clock output.
This pin also serves as the select strap (associates with SEL0 &
1, see app. note page 5) for clock frequencies during power up.
Refer to Table 1 for detail. This pin has an internal pull-down
(Typ. 70KΩ).
3 XIN VDD I OSC1 14.318MHz Crystal input
4
XOUT
VDD O
14.318MHz Crystal output
11, 12, 13,
15, 16, 18,
19, 20
PCI0/ICH
PCI(1..7)
VDD O
3.3V PCI clock outputs
7, 8
3V66(0,1)
VDD O
3.3V Fixed 66.6 MHz clock outputs
25 USB VDD O 3.3V Fixed 48 MHz clock outputs
26 DOT VDD O 3.3V Fixed 48 MHz clock outputs
28, 29
SEL(0,1)
VDD I
3.3V LVTTL compatible inputs for logic selection. Has an
internal pull-up (Typ. 250KΩ)
30
SDATA
VDD I
I²C compatible SDATA input. Has an internal pull-up (>100KΩ)
31
SCLK
VDD I
I²C compatible SCLK input. Has an internal pull-up (>100KΩ)
32 PD# VDD I 3.3V LVTTL compatible input. Device enters powerdown mode
When held LOW. Has an internal pull-up (>100KΩ)
34
DCLK
VDD O
3.3V output running 100MHz
36, 37, 39, SDRAM(7..0) VDDS O
3.3V output running 100MHz. All SDRAM outputs can be turned
40, 42, 43,
off through SMBUS.
45, 46
49, 50, 52
CPU(2)_ITP, VDDC O
CPU(1,0)
2.5V Host bus clock outputs. 66, 100 or 133MHz depending on
state of SEL(2..0)
54, 55
IOAPIC(1,0) VDDI O
2.5V clock outputs running rising edge synchronous with the
PCI clock.
2, 9, 10, 21, VDD
27, 33
-
3.3V Power Supply
22 VDDA -
Analog circuitry 3.3V Power Supply
23 VSSA
-
Analog circuitry power supply Ground pins.
51, 53
VDDC, VDDI
-
2.5V Power Supply’s
5, 6,14, 17, VSS
24, 35, 41,
- - Common Ground pins.
47, 48, 56
38, 44
VDDS
- - 3.3V power support for SDRAM clock output drivers.
A bypass capacitor (0.1µF) should be placed as close as possible to each positive power pin. If these bypass capacitors
are not close to the pins their high frequency filtering characteristic will be cancelled by the lead inductance of the traces.
Cypress Semiconductor Corporation
525 Los Coches St.
Milpitas, CA 95035. Tel: 408-263-6300, Fax: 408-263-6571
http://www.cypress.com
Document#: 38-07053 Rev. **
05/03/01
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