APPROVED PRODUCT
C9812
Low EMI Clock Generator for Intel 810E Chipset Systems
Pin Description
PIN No.
Pin Name
PWR
VDD
I/O TYPE
I/O
Description
3.3V 14.318 MHz clock output.
1
SEL2/REF
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
4
VDD
VDD
VDD
I
O
O
OSC1 14.318MHz Crystal input
XIN
XOUT
PCI0/ICH
PCI(1..7)
14.318MHz Crystal output
3.3V PCI clock outputs
11, 12, 13,
15, 16, 18,
19, 20
7, 8
25
26
VDD
VDD
VDD
VDD
O
O
O
I
3.3V Fixed 66.6 MHz clock outputs
3.3V Fixed 48 MHz clock outputs
3.3V Fixed 48 MHz clock outputs
3.3V LVTTL compatible inputs for logic selection. Has an
internal pull-up (Typ. 250KΩ)
3V66(0,1)
USB
DOT
28, 29
SEL(0,1)
30
31
32
VDD
VDD
VDD
I
I
I
SDATA
SCLK
PD#
I²C compatible SDATA input. Has an internal pull-up (>100KΩ)
I²C compatible SCLK input. Has an internal pull-up (>100KΩ)
3.3V LVTTL compatible input. Device enters powerdown mode
When held LOW. Has an internal pull-up (>100KΩ)
3.3V output running 100MHz
34
VDD
VDDS
O
O
DCLK
SDRAM(7..0)
36, 37, 39,
40, 42, 43,
45, 46
3.3V output running 100MHz. All SDRAM outputs can be turned
off through SMBUS.
49, 50, 52
VDDC
VDDI
-
O
O
2.5V Host bus clock outputs. 66, 100 or 133MHz depending on
state of SEL(2..0)
2.5V clock outputs running rising edge synchronous with the
PCI clock.
3.3V Power Supply
CPU(2)_ITP,
CPU(1,0)
IOAPIC(1,0)
54, 55
2, 9, 10, 21,
27, 33
VDD
22
23
51, 53
5, 6,14, 17,
24, 35, 41,
47, 48, 56
38, 44
-
-
-
-
Analog circuitry 3.3V Power Supply
Analog circuitry power supply Ground pins.
2.5V Power Supply’s
VDDA
VSSA
VDDC, VDDI
VSS
-
-
Common Ground pins.
-
3.3V power support for SDRAM clock output drivers.
VDDS
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.
Document#: 38-07053 Rev. **
05/03/01
Milpitas, CA 95035. Tel: 408-263-6300, Fax: 408-263-6571
http://www.cypress.com
Page 2 of 18
CYPRESS [ CYPRESS ]
