CY28325PVC-2 Cypress Semiconductor Corp., CY28325PVC-2 Datasheet - Page 2

• Manufacturer Part Number: CY28325PVC-2
• Description: Frequency Timing Generators For PC And Server Motherboards
• Manufacturer: Cypress Semiconductor Corp.

Pin Definitions
Document #: 38-07119 Rev. *A
Pin Name
X1
X2
REF/FS4
CPUT_0:1
CPUC_0:1
CPUT_CS_F
CPUC_CS_F
APIC0:1
AGP 0:2
PCI_F/FS0
PCI1/FS1
PCI2/MULTSEL
1
PCI3:8
48MHz/FS3
24_48MHz/FS2
CPU_STOP#
PCI_ST0P#
PD#
SCLK
SDATA
RST#
IREF
14, 15, 17, 18,
40, 39, 35, 34
23, 26, 27
Pin No.
42, 41
46, 45
19, 21
10
12
32
31
22
28
29
30
37
11
4
5
1
7
8
(open-d
Type
PRELIMINARY
rain)
Pin
I/O
I/O
I/O
I/O
I/O
I/O
I/O
O
O
O
O
O
O
O
I
I
I
I
I
I
Pin Description
Crystal Connection or External Reference Frequency Input: This pin has
dual functions. It can be used as an external 14.318-MHz crystal connection or
as an external reference frequency input.
Crystal Connection: Connection for an external 14.318-MHz crystal. If using an
external reference, this pin must be left unconnected.
Reference Clock Output/Frequency Select 4: 3.3V 14.318-MHz output. This
pin also serves as a power-on strap option to determine device operating fre-
quency as described in the Frequency Selection Table.
CPU Clock Outputs: Frequency is set by the FS0:4 inputs or through serial
input interface.
CPU Clock Outputs for Chipset: Frequency is set by the FS0:4 inputs or
through serial input interface.
APIC Clock Output: APIC clock outputs running at half of PCI output frequency.
AGP Clock Output: 3.3V AGP clock.
Free-running PCI Output 1/Frequency Select 1: 3.3V free-running PCI output.
This pin also serves as a power-on strap option to determine device operating
frequency as described in the Frequency Selection Table.
PCI Output 1 /Frequency Select 1: 3.3V PCI output. This pin also serves as a
power-on strap option to determine device operating frequency as described in
the Frequency Selection Table.
PCI Output 2/Current Multiplier Selection 1: 3.3V PCI output. This pin also
serves as a power-on strap option to determine the current multiplier for the CPU
clock outputs. The MULTSEL definitions are as follows:
MULTISEL
0 = Ioh is 4 × IREF
1 = Ioh is 6 × IREF
PCI Clock Output 3 to 8: 3.3V PCI clock outputs.
48-MHz Output/Frequency Select 3: 3.3V fixed 48-MHz, non-spread spectrum
output. This pin also serves as a power-on strap option to determine device
operating frequency as described in the Frequency Selection Table.
24- or 48-MHz Output/Frequency Select 2: 3.3V fixed 24- or 48-MHz
non-spread spectrum output. This pin also serves as a power-on strap option to
determine device operating frequency as described in the Frequency Selection
Table.
CPU Output Control: 3.3V LVTTL-compatible input that disables CPUT_CS,
CPUC_CS, CPUT_0:1 and CPUC_0:1.
PCI Output Control: 3.3V LVTTL-compatible input that disables PCI1:8.
Power-down Control: 3.3V LVTTL-compatible input that places the device in
power down mode when held LOW.
SMBus Clock Input: Clock pin for serial interface.
SMBus Data Input: Data pin for serial interface.
System Reset Output: Open-drain system reset output.
Current Reference for CPU output: A precision resistor is attached to this pin,
which is connected to the internal current reference.
CY28325-2
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