CY28409 Cypress Semiconductor, CY28409 Datasheet - Page 2

• Manufacturer Part Number: CY28409
• Description: Clock Synthesizer with Differential SRC and CPU Outputs
• Manufacturer: Cypress Semiconductor

Document #: 38-07445 Rev. *B
Pin Description
1, 2
4
5
41,44,47
40,43,46
38, 37
22,23,26,27
29
7,8,9
12,13,14,
15,18,19,20
31,
32
51,56
52
21
50
49
35
30
28
53
55
54
42,48
45
36
39
34
33
10,16
11,17
24
25
3
6
Pin No.
3V66(0:3)
FS_A, FS_B
VSS_IREF
REF(0:1)
XIN
XOUT
CPUT(0:2)
CPUC(0:2)
SRCT, SRCC
3V66_4VCH
PCIF(0:2)
PCI(0:6)
USB_48
DOT_48
IREF
PD#
CPU_STP#
PCI_STP#
VTT_PWRGD#
SDATA
SCLK
VDD_A
VSS_A
VDD_CPU
VSS_CPU
VDD_SRC
VSS_SRC
VDD_48
VSS_48
VDD_PCI
VSS_PCI
VDD_3V66
VSS_3V66
VDD_REF
VSS_REF
Name
O, DIF CPU Clock Output. Differential CPU clock outputs. See Table 1 for frequency config-
O, DIF CPU Clock Output. Differential CPU clock outputs. See Table 1 for frequency config-
O, DIF Differential serial reference clock.
O, SE Reference Clock. 3.3V 14.318-Mz clock output.
O, SE Crystal Connection. Connection for an external 14.318-MHz crystal output.
O, SE 66-MHz Clock Output. 3.3V 66-MHz clock from internal VCO.
O, SE 48-/66-MHz Clock Output. 3.3V selectable through SMBus to be 66 or 48 MHz.
O, SE Free-running PCI Output. 33-MHz clocks divided down from 3V66.
O, SE PCI Clock Output. 33-MHz clocks divided down from 3V66.
O, SE Fixed 48-MHz clock output.
O, SE Fixed 48-MHz clock output.
PWR 3.3V power supply for PLL.
PWR 3.3V power supply for outputs.
PWR 3.3V power supply for outputs.
PWR 3.3V power supply for outputs.
PWR 3.3V power supply for outputs.
PWR 3.3V power supply for outputs.
PWR 3.3V power supply for outputs.
I, PU 3.3V LVTTL input for PowerDown# active low.
I, PU 3.3V LVTTL input for CPU_STP# active low.
I, PU
GND
GND
GND
GND
GND
GND
GND
GND
Type
I/O
I
I
I
I
I
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.
uration
uration
3.3V LVTTL input for CPU frequency selection.
Current Reference. A precision resistor is attached to this pin which is connected to
the internal current reference.
3.3V LVTTL input for PCI_STP# active low.
3.3V LVTTL input is a level sensitive strobe used to latch the FS_A and FS_B
inputs (active low).
SMBus-compatible SDATA.
SMBus-compatible SCLOCK.
Ground for current reference.
Ground for PLL.
Ground for outputs.
Ground for outputs.
Ground for outputs.
Ground for outputs.
Ground for outputs.
Ground for outputs.
Description
CY28409
Page 2 of 18