900,000+ datasheet pdf search and download

Datasheet4U offers most rated semiconductors data sheet pdf




Cypress Semiconductor Electronic Components Datasheet

W48S87-04 Datasheet

Spread Spectrum 3 DIMM Desktop Clock

No Preview Available !

PRELIMINARY
W48S87-04
Spread Spectrum 3 DIMM Desktop Clock
Features
• Outputs
— 4 CPU Clock (2.5V or 3.3V, 50 to 83.3 MHz)
— 7 PCI (3.3V)
— 1 48-MHz for USB (3.3V)
— 1 24-MHz for Super I/O (3.3V)
— 2 REF (3.3V)
— 1 IOAPIC (2.5V or 3.3V)
— 12 SDRAM
• Serial data interface provides additional frequency
selection, individual clock output disable, and other
functions
• Smooth transition supports dynamic frequency
assignment
• Frequency selection not affected during power
down/up cycle
• Supports a variety of power-saving options
• 3.3V operation
• Available in 48-pin SSOP (300 mils)
Key Specifications
±0.5% Spread Spectrum Modulation: ......................... ±0.5%
Jitter (Cycle-to-Cycle): .................................................250 ps
Duty Cycle: ................................................................ 45-55%
CPU-PCI Skew: ........................................................ 1 to 4 ns
PCI-PCI or CPU-CPU Skew: .......................................250 ps
Table 1. Pin Selectable Frequency[1]
Input Address
FS2 FS1 FS0
CPU, SDRAM
Clocks (MHz)
PCI Clocks
(MHz)
000
50.0
25.0
001
75.0
32.0
010
83.3
41.65
011
68.5
34.25
100
55.0
27.5
101
75.0
37.5
110
60.0
30.0
111
66.8
33.4
Block Diagram
Pin Configuration[2]
SDATA
SCLOCK
X1
X2
CPU3.3#_2.5
FS0
FS1
FS2
CPU_STOP#
Serial Port
XTAL OSC
Device
Control
PLL Ref
Freq
VDD1
CPU Clock
Mode Control
Freq
Select
I/O
MODE
REF0/CPU3.3#_2.5
REF1(CPU_STOP#)
VDDL1
PLL1
Stop
Clock
Cntrl
IOAPIC
VDDL2
4 CPU0:3
VDD3
12 SDRAM0:11
÷2 VDD2
VDD1
REF0/CPU3.3#_2.5
GND
X1
X2
VDD2
PCI_F/FS1
PCI0/FS2
GND
PCI1
PCI2
PCI3
PCI4
VDD2
PCI5(PWR_DWN#)
GND
SDRAM11
SDRAM10
VDD3
SDRAM9
SDRAM8
GND
SDATA
SCLOCK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
I/O PCI_F/FS1
I/O PCI0/FS2
4 PCI1:4
PWR_DWN#
Power Down MODE
Control
PCI5(PWR_DWN#)
VDD1
PLL2
÷2
÷4
I/O 48MHZ/FS0
I/O 24MHZ/MODE
Notes:
1. Additional frequency selections provided by serial data interface; refer to Table 5 on page 10.
2. Signal names in parenthesis denotes function is selectable through mode pin register strapping.
48 VDDL1
47 IOAPIC
46 REF1(CPU_STOP#)
45 GND
44 CPU0
43 CPU1
42 VDDL2
41 CPU2
40 CPU3
39 GND
38 SDRAM0
37 SDRAM1
36 VDD3
35 SDRAM2
34 SDRAM3
33 GND
32 SDRAM4
31 SDRAM5
30 VDD3
29 SDRAM6
28 SDRAM7
27 GND
26 48MHZ/FS0
25 24MHZ/MODE
Cypress Semiconductor Corporation • 3901 North First Street • San Jose • CA 95134 • 408-943-2600
October 19, 1999, rev. **


Cypress Semiconductor Electronic Components Datasheet

W48S87-04 Datasheet

Spread Spectrum 3 DIMM Desktop Clock

No Preview Available !

PRELIMINARY
W48S87-04
Pin Definitions
Pin Name
CPU0:3
PCI_F/FS1
PCI0/FS2
PCI1:4
PCI5(PWR_DWN#)
SDRAM0:11
IOAPIC
48MHZ/FS0
24MHZ/MODE
Pin
No.
44, 43, 41,
40
7
8
10, 11, 12,
13
15
38, 37, 35,
34, 32, 31,
29, 28, 21,
20, 18, 17
47
26
25
Pin
Type
O
I/O
I/O
O
I/O
O
Pin Description
CPU Clock Outputs 0 through 3: These four CPU clock outputs are controlled
by the CPU_STOP# control pin. Output voltage swing is controlled by voltage
applied to VDDL2 and output characteristics are adjusted by input
CPU3.3#_2.5.
Fixed PCI Clock Output and Frequency Selection Bit 1: As an output, this
pin works in conjunction with PCI0:5. Output voltage swing is controlled by
voltage applied to VDD2.
When an input, this pin functions as part of the frequency selection address.
The value of FS0:2 determines the power-up default frequency of device output
clocks as per the Table 1, Pin Selectable Frequencyon page 1.
PCI Bus Clock Output 0 and Frequency Selection Bit 2: As an output, this
pin works in conjunction with PCI1:5 and PCI_F. Output voltage swing is con-
trolled by voltage applied to VDD2.
When an input, this pin functions as part of the frequency selection address.
The value of FS0:2 determines the power-up default frequency of device output
clocks as per the Table 1, Pin Selectable Frequencyon page 1.
PCI Bus Clock Outputs 1 through 4: Output voltage swing is controlled by
voltage applied to VDD2.
PCI Bus Clock Output 5 or Power-Down Control: As an output, this pin works
in conjunction with PCI0:4 and PCI_F. Output voltage swing is controlled by
voltage applied to VDD2.
If programmed as an input (refer to MODE pin description), this pin is used for
power-down control. When LOW, the device goes into a low-power standby
condition. All outputs are actively held LOW while in power-down. CPU,
SDRAM, and PCI clock outputs are stopped LOW after completing a full clock
cycle (24 CPU clock cycle latency). When brought HIGH, CPU, SDRAM, and
PCI outputs start with a full clock cycle at full operating frequency (3 ms max-
imum latency).
SDRAM Clock Outputs 0 through 11: These twelve SDRAM clock outputs
run synchronous to the CPU clock outputs. Output voltage swing is controlled
by voltage applied to VDD3.
O I/O APIC Clock Output: Provides 14.318-MHz fixed frequency. The output
voltage swing is controlled by VDDL1.
I/O 48-MHz Output and Frequency Selection Bit 0: Fixed clock output that de-
faults to 48 MHz following device power-up. Output voltage swing is controlled
by voltage applied to VDD1.
When an input, this pin functions as part of the frequency selection address.
The value of FS0:2 determines the power-up default frequency of device output
clocks as per the Table 1, Pin Selectable Frequencyon page 1.
I/O 24-MHz Output and Mode Control Input: Fixed clock output that defaults to
24 MHz following device power-up. Output voltage swing is controlled by volt-
age applied to VDD1.
When an input, this pin is used for pin programming selection. It determines
the functions for pins 15 and 46:
MODE
Pin 15
Pin 46
0 PWR_DWN# (input) CPU_STOP# (input)
1 PCI5 (output)
REF1 (output)
2


Part Number W48S87-04
Description Spread Spectrum 3 DIMM Desktop Clock
Maker Cypress Semiconductor
PDF Download

W48S87-04 Datasheet PDF






Similar Datasheet

1 W48S87-04 Spread Spectrum 3 DIMM Desktop Clock
Cypress Semiconductor
2 W48S87-04 Spread Spectrum 3 DIMM Desktop Clock
IC WORKS





Part Number Start With

0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z

Site map

Webmaste! click here

Contact us

Buy Components

Privacy Policy