CYPRESS W167B

PRELIMINARY
W167B
133-MHz Spread Spectrum FTG for Pentium® II Platforms
Features
Duty Cycle: ................................................................ 45/55%
• Maximized EMI Suppression using Cypress’s Spread
Spectrum technology
• Three copies of CPU outputs selectable frequency
• Three copies of 3V66 selectable frequency output at
3.3V
• Ten copies of PCI clocks (selectable frequency), 3.3V
• One double strength 14.318-MHz reference output at
3.3V
• One copy of 48-MHz USB clock
• One copy of selectable 24-/48-MHz for SIO
• One copy of CPU-divide-by-2 output as reference input
to Direct Rambus™ Clock Generator (Cypress W134)
• Three copies of IOAPIC
• Available in 48-pin SSOP (300 mils)
Key Specifications
Supply Voltages: ...................................... VDDQ2 = 2.5V±5%
VDDQ3 = 3.3V±5%
CPU, CPUdiv2 Output Jitter:....................................... 250 ps
CPU, CPUdiv2 Output Skew: ...................................... 175 ps
IOAPIC, 3V66 Output Skew: ....................................... 250 ps
PCI0:8 Pin to Pin Skew: .............................................. 500 ps
Spread Spectrum Modulation:................................... ±0.25%
CPU to 3V66 Output Offset: ............. 0.0–1.5 ns (CPU leads)
3V66 to PCI Output Offset:.............. 1.5–4.0 ns (3V66 leads)
CPU to IOAPIC Output Offset: ......... 1.5–4.0 ns (CPU leads)
Table 1. Pin Selectable Frequency
SEL133/
CPU
100# SEL2 SEL1 SEL0 MHz
1
1
1
1
133.3
1
1
1
0
138
1
1
0
1
143
1
1
0
0
148
1
0
1
1
150
1
0
1
0
152.5
1
0
0
1
155
1
0
0
0
160
0
1
1
1
100.2
0
1
1
0
105
0
1
0
1
114
0
1
0
0
120
0
0
1
1
66.8
0
0
1
0
124
0
0
0
1
128.5
0
0
0
0
133.9
Block Diagram
Pin Configuration
3V66
MHz
66.7
69
71.5
74
75
76.3
77.5
80
66.8
70
76
80
66.8
82.7
64.3
67
PCI IOAPIC
MHz MHz
33.3 16.7
34.5 17.3
35.8 17.9
37
18.5
37.5 18.8
38.1 19.1
38.8 19.4
40
20
33.4 16.7
35
17.5
38
19
40
20
33.4 16.7
41.3 20.7
32.1 16.1
33.5 16.7
[1]
VDDQ3
X1
X2
XTAL
OSC
REF2X
VDDQ2
3
÷2
SEL133/100#
CPU_[0:2]
CPUdiv2
PLL 1
VDDQ3
3V66_[0:2]
÷2/÷1.5
3
PCI0/SEL2*
PCI1/SEL1*
÷2
PWRDWN#
PCI_[2:9]
8
VDDQ2
Power
Down
Logic
÷2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
W167B
IOAPIC2
REF2X
VDDQ3
X1
X2
GND
SEL2*/PCI0
SEL1*/PCI1
VDDQ3
PCI2
PCI3
PCI4
PCI5
GND
PCI6
PCI7
VDDQ3
PCI8
PCI9
GND
3V66_0
3V66_1
3V66_2
VDDQ3
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
GND
VDDQ2
IOAPIC0
IOAPIC1
GND
VDDQ2
CPUdiv2
GND
VDDQ2
CPU2
GND
VDDQ2
CPU1
CPU0
SDATA
VDDQ3
GND
PWRDN#*
SCLK
VDDQ3
SIO/24_48#MHz*
48MHz/SEL0*
GND
SEL133/100#
IOAPIC[0:2]
3
Q#
VDDQ3
PLL2
SDATA
SCLK
48MHz/SEL0*
÷2
Note:
1. Internal 250-kΩ pull-up resistors present on inputs marked with *.
Design should not rely solely on internal pull-up resistor to set I/O
pins HIGH.
SIO/24_48#MHz
Serial
Logic
Direct Rambus is a trademark of Rambus, Inc. Pentium is a registered trademark of Intel Corporation.
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
November 2, 1999
PRELIMINARY
W167B
Pin Definitions
Pin
No.
Pin
Type
35, 36, 39
O
CPU Clock Outputs 0 through 2: CPU clock outputs. Their output voltage
swing is controlled by voltage applied to VDDQ2.
SEL133/100#
25
I
SEL133/100#: Frequency selection input pin as shown in Table 1.
PCI0/SEL2
7
I/O
PCI Clock Output 0 and Selection Bit 2: As an output, this pin works in
conjunction with PCI2:9. When an input, this pin functions as part of the frequency selection address (see Table 1).
PCI1/SEL1
8
I/O
PCI Clock Output 1 and Selection Bit 1: As an output, this pin works in
conjunction with PCI2:9. When an input, this pin functions as part of the frequency selection address (see Table 1).
PCI2:9
10, 11, 12,
13, 15, 16,
18, 19
O
PCI Clock Outputs 2 through 9: Output voltage swing is controlled by voltage
applied to VDDQ3.
3V66_0:2
21, 22, 23
O
66-MHz Clock Outputs 0 through 2: Output voltage swing is controlled by
voltage applied to VDDQ3.
CPUdiv2
42
O
CPU-Divide-By-2 Output: This serves as a reference input signal for Direct
Rambus Clock Generator (Cypress W134). The output voltage is determined
by VDDQ2.
46, 45, 1
O
I/O APIC Clock Output 0 through 2: Provide outputs synchronous to CPU
clock. See Table 1 and Table 5 for their relation to other system clock outputs.
48MHZ/SEL0
27
I/O
48-MHz Output and Selection Bit 0: Fixed clock output that defaults to
48-MHz following device power-up. When an input, this pin functions as part of
the frequency selection address (see Table 1).
SIO/24_48#MHz
28
I/O
Super I/O Reference Clock Output and SIO Clock Frequency Select: Fixed
clock output that provides the reference input clock to a Super I/O device. The
output frequency is determined by the input value on this pin during power up.
If input is sampled HIGH, the output operates at 24 MHz, otherwise, the output
operates at 48 MHz.
REF2X
2
O
Fixed 14.318-MHz Output: With double strength driving capability.
PWRDWN#
31
I
Power Down Control
X1
4
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.
X2
5
I
Crystal Connection: An input connection for an external 14.318-MHz crystal.
If using an external reference, this pin must be left unconnected.
SDATA
34
I/O
SCLK
30
I
Serial Clock Input: Clock input for Serial Data Interface. Refer to Serial Data
Interface section that follows.
VDDQ2
37, 40, 43, 47
P
Power Connection: Connected to 2.5V power supply.
VDDQ3
3, 9, 17, 24,
29, 33
P
Power Connection: Connected to 3.3V supply.
GND
6, 14, 20, 26,
32, 38, 41,
44, 48
G
Ground Connection: Connect all ground pins to the common system ground
plane.
Pin Name
CPU0:2
IOAPIC0:2
Pin Description
Serial Data Input: Data input for Serial Data Interface. Refer to Serial Data
Interface section that follows.
2
PRELIMINARY
W167B
on each l/O pin to pull the pin and its associated capacitive
clock load to either a logic HIGH or LOW state. At the end of
the 2-ms period, the established logic 0 or 1 condition of each
l/O pin is then latched. Next, the output buffers are enabled,
converting the l/O pins into operating clock outputs. The 2-ms
timer starts when VDD reaches 2.0V. The input bits can only
be reset by turning VDD off and then back on again.
Overview
The W167B, a motherboard clock synthesizer, provides 2.5V
CPU clock outputs for advanced CPU and a CPU-divide-by-2
reference frequency for Direct Rambus Clock Generator (such
as Cypress W134) interface. Fixed output frequencies are provided for other system functions.
It should be noted that the strapping resistors have no significant effect on clock output signal integrity. The drive impedance of the clock outputs is <40Ω (nominal) which is minimally
affected by the 10-kΩ strap to ground or VDD. As with the series termination resistor, the output strapping resistor should
be placed as close to the l/O pin as possible in order to keep
the interconnecting trace short. The trace from the resistor to
ground or VDD should be kept less than two inches in length to
prevent system noise coupling during input logic sampling.
I/O Pin Operation
Pins 7, 8, 27, and 28 are dual-purpose l/O pins. Upon powerup these pins act as logic inputs, allowing the determination of
assigned device functions. A short time after power-up, the
logic state of these pins is latched and the pins then become
clock outputs. This feature reduces device pin count by combining clock outputs with input select pins.
An external 10-kΩ “strapping” resistor is connected between
each l/O pin and ground or VDD3. Connection to ground sets a
latch to “0”, connection to V DD3 sets a latch to “1”. Figure 1 and
Figure 2 show two suggested methods for strapping resistor
connection.
When the clock outputs are enabled following the 2-ms input
period, target (normal) output frequency is delivered assuming
that VDD has stabilized. If VDD has not yet reached full value,
output frequency initially may be below target but will increase
to target once VDD voltage has stabilized. In either case, a
short output clock cycle may be produced from the CPU clock
outputs when the outputs are enabled.
Upon W167B power up, the first 2 ms of operation is used for
input logic selection. During this period, these dual-purpose
I/O pins are three-stated, allowing the output strapping resistor
VDD
Output Strapping Resistor
Series Termination Resistor
10 kΩ
(Load Option 1)
W167B
Power-on
Reset
Timer
Hold
Output
Low
Output Three-state
Q
Clock Load
R
Output
Buffer
10 kΩ
(Load Option 0)
D
Data
Latch
Figure 1. Input Logic Selection Through Resistor Load Option
Jumper Options
Output Strapping Resistor
VDD
Series Termination Resistor
10 kΩ
W167B
R
Output
Buffer
Power-on
Reset
Timer
Hold
Output
Low
Output Three-state
Q
D
Data
Latch
Figure 2. Input Logic Selection Through Jumper Option
3
Clock Load
PRELIMINARY
W167B
CPU/PCI Frequency Selection
Crystal Oscillator
CPU frequency is selected with I/O pins 7, 8, 27, (SEL2/PCI0,
SEL1/PCI1, 48MHz/SEL0, respectively) and input pin 25
(SEL133/100#). Refer to Table 1 for CPU/PCI frequency programming information. Additional frequency selections are
available through the serial data interface. Refer to Table 5 on
page 9.
The W167B requires one input reference clock to synthesize
all output frequencies. The reference clock can be either an
externally generated clock signal or the clock generated by the
internal crystal oscillator. When using an external clock signal,
pin X1 is used as the clock input and pin X2 is left open.
The internal crystal oscillator is used in conjunction with a
quartz crystal connected to device pins X1 and X2. This forms
a parallel resonant crystal oscillator circuit. The W167B incorporates the necessary feedback resistor and crystal load capacitors. Including typical stray circuit capacitance, the total
load presented to the crystal is approximately 18 pF. For optimum frequency accuracy without the addition of external capacitors, a parallel-resonant mode crystal specifying a load of
18 pF should be used. This will typically yield reference frequency accuracies within ±100 ppm.
Output Buffer Configuration
Clock Outputs
All clock outputs are designed to drive serial terminated clock
lines. The W167B outputs are CMOS-type which provide railto-rail output swing.
4
PRELIMINARY
W167B
Spread Spectrum Feature
Where P is the percentage of deviation and F is the frequency
in MHz where the reduction is measured.
The device generates a clock that is frequency modulated in
order to increase the bandwidth that it occupies. By increasing
the bandwidth of the fundamental and its harmonics, the amplitudes of the radiated electromagnetic emissions are reduced. This effect is depicted in Figure 3.
The output clock is modulated with a waveform depicted in
Figure 4. This waveform, as discussed in “Spread Spectrum
Clock Generation for the Reduction of Radiated Emissions” by
Bush, Fessler, and Hardin produces the maximum reduction
in the amplitude of radiated electromagnetic emissions. The
deviation selected for this chip is –0.5% downspread. Figure 4
details the Cypress spreading pattern. Cypress does offer options with more spread and greater EMI reduction. Contact
your local Sales representative for details on these devices.
As shown in Figure 3, a harmonic of a modulated clock has a
much lower amplitude than that of an unmodulated signal. The
reduction in amplitude is dependent on the harmonic number
and the frequency deviation or spread. The equation for the
reduction is
dB = 6.5 + 9*log10(P) + 9*log10(F)
EMI Reduction
Spread
Spectrum
Enabled
NonSpread
Spectrum
Time
Figure 4. Typical Modulation Profile
5
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
100%
90%
80%
70%
60%
50%
40%
30%
20%
100%
80%
60%
40%
20%
0%
–20%
–40%
–60%
–80%
–100%
10%
Frequency Shift
Figure 3. Typical Clock and SSFTG Comparison
PRELIMINARY
W167B
SDATA and SCLOCK. In motherboard applications, SDATA
and SCLOCK are typically driven by two logic outputs of the
chipset. Clock device register changes are normally made
upon system initialization, if any are required. The interface
can also be used during system operation for power management functions. Table 2 summarizes the control functions of
the serial data interface.
Serial Data Interface
The W167B features a two-pin, serial data interface that can
be used to configure internal register settings that control particular device functions. Upon power-up, the W167B initializes
with default register settings, therefore the use of this serial
data interface is optional. The serial interface is write-only (to
the clock chip) and is the dedicated function of device pins
Table 2. Serial Data Interface Control Functions Summary
Control Function
Description
Common Application
Clock Output Disable
Any individual clock output(s) can be disabled. Dis- Unused outputs are disabled to reduce EMI
abled outputs are actively held LOW.
and system power. Examples are clock outputs to unused SDRAM DIMM socket or PCI
slot.
CPU Clock Frequency
Selection
Provides CPU/PCI frequency selections. Frequency is changed in a smooth and controlled fashion.
For alternate CPU devices, and power management options. Smooth frequency transition allows CPU frequency change under normal system operation.
Output Three-state
Puts all clock outputs into a high-impedance state.
Production PCB testing.
Test Mode
All clock outputs toggle in relation with X1 input,
internal PLL is bypassed. Refer to Table 4.
Production PCB testing.
(Reserved)
Reserved function for future device revision or pro- No user application. Register bit must be writduction device testing.
ten as 0.
Operation
Data is written to the W167B in ten bytes of eight bits each. Bytes are written in the order shown in Table 3.
Table 3. Byte Writing Sequence
Byte Sequence
Byte Name
1
Slave Address
11010010
Bit Sequence
Commands the W167B to accept the bits in Data Bytes 0–6 for internal
register configuration. Since other devices may exist on the same common serial data bus, it is necessary to have a specific slave address for
each potential receiver. The slave receiver address for the W167B is
11010010. Register setting will not be made if the Slave Address is not
correct (or is for an alternate slave receiver).
Byte Description
2
Command
Code
Don’t Care
Unused by the W167B, therefore bit values are ignored (don’t care). This
byte must be included in the data write sequence to maintain proper byte
allocation. The Command Code Byte is part of the standard serial communication protocol and may be used when writing to another addressed slave receiver on the serial data bus.
3
Byte Count
Don’t Care
Unused by the W167B, therefore bit values are ignored (don’t care). This
byte must be included in the data write sequence to maintain proper byte
allocation. The Byte Count Byte is part of the standard serial communication protocol and may be used when writing to another addressed
slave receiver on the serial data bus.
4
Data Byte 0
Refer to Table 4
5
Data Byte 1
6
Data Byte 2
The data bits in these bytes set internal W167B registers that control
device operation. The data bits are only accepted when the Address
Byte bit sequence is 11010010, as noted above. For description of bit
control functions, refer to Table 4, Data Byte Serial Configuration Map.
7
Data Byte 3
8
Data Byte 4
9
Data Byte 5
10
Data Byte 6
6
PRELIMINARY
Writing Data Bytes
W167B
7. Table 4 gives the bit formats for registers located in Data
Bytes 0–6. Table 5 details additional frequency selections that
are available through the serial data interface. Table 6 details
the select functions for Byte 0, bits 1 and 0.
Each bit in the data bytes control a particular device function
except for the “reserved” bits which must be written as a logic
0. Bits are written MSB (most significant bit) first, which is bit
Table 4. Data Bytes 0–6 Serial Configuration Map
Affected Pin
Bit(s)
Pin No.
Bit Control
Pin Name
Control Function
0
1
Default
Data Byte 0
7
--
--
SEL133/100#
Refer to Table 5
0
6
--
--
SEL2
Refer to Table 5
0
5
--
--
SEL1
Refer to Table 5
0
4
--
--
SEL0
Refer to Table 5
0
3
--
--
Frequency Table Selection
2
--
--
(Reserved)
1-0
--
--
Functional control
7
27
48MHz
Clock Output Disable
Low
Active
1
6
28
24/48MHz
Clock Output Disable
Low
Active
1
5
--
--
--
--
0
4
42
CPUdiv2
Low
Active
1
3
--
--
--
--
0
2
39
CPU2
Clock Output Disable
Low
Active
1
1
36
CPU1
Clock Output Disable
Low
Active
1
0
35
CPU0
Clock Output Disable
Low
Active
1
Controlled by external pin (per Table 1)
Controlled by BYTE0
(per Table 5)
--
-Refer to Table 6
0
0
00
Data Byte 1
(Reserved)
Clock Output Disable
(Reserved)
Data Byte 2
7
16
PCI7
Clock Output Disable
Low
Active
1
6
15
PCI6
Clock Output Disable
Low
Active
1
5
13
PCI5
Clock Output Disable
Low
Active
1
4
12
PCI4
Clock Output Disable
Low
Active
1
3
11
PCI3
Clock Output Disable
Low
Active
1
2
10
PCI2
Clock Output Disable
Low
Active
1
1
8
PCI1
Clock Output Disable
Low
Active
1
0
7
PCI0
Clock Output Disable
Low
Active
1
--
--
0
Data Byte 3
7
--
--
(Reserved)
6
23
3V66_2
Clock Output Disable
Low
Active
1
5
22
3V66_1
Clock Output Disable
Low
Active
1
4
21
3V66_0
Clock Output Disable
Low
Active
1
3
--
--
(Reserved)
--
--
0
2
--
--
(Reserved)
--
--
0
1
19
PCI9
Clock Output Disable
Low
Active
1
0
18
PCI8
Clock Output Disable
Low
Active
1
7
PRELIMINARY
W167B
Table 4. Data Bytes 0–6 Serial Configuration Map (continued)
Affected Pin
Bit(s)
Pin No.
Pin Name
Bit Control
Control Function
0
1
Default
Data Byte 4
7
--
--
--
--
0
6
1
IOAPIC2
(Reserved)
Clock Output Disable
Low
Active
1
5
45
IOAPIC1
Clock Output Disable
Low
Active
1
4
46
IOAPIC0
Clock Output Disable
Low
Active
1
3
--
--
(Reserved)
--
--
0
2
--
--
(Reserved)
--
--
0
1
--
--
(Reserved)
--
--
0
0
2
REF2X
Low
Active
1
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
--
--
--
(Reserved)
--
--
0
Clock Output Disable
Data Byte 5
Data Byte 6
8
PRELIMINARY
W167B
Table 5. Additional Frequency Selections through Serial Data Interface Data Bytes
SEL133/100#
SEL2
SEL1
SEL0
CPU
MHz
3V66
MHz
PCI
MHz
IOAPIC
MHz
1
1
1
1
133.3
66.7
33.3
16.7
1
1
1
0
138
69
34.5
17.3
1
1
0
1
143
71.5
35.8
17.9
1
1
0
0
148
74
37
18.5
1
0
1
1
150
75
37.5
18.8
1
0
1
0
152.5
76.3
38.1
19.1
1
0
0
1
155
77.5
38.8
19.4
1
0
0
0
160
80
40
20
0
1
1
1
100.2
66.8
33.4
16.7
0
1
1
0
105
70
35
17.5
0
1
0
1
114
76
38
19
0
1
0
0
120
80
40
20
0
0
1
1
66.8
66.8
33.4
16.7
0
0
1
0
124
82.7
41.3
20.7
0
0
0
1
128.5
64.3
32.1
16.1
0
0
0
0
133.9
67
33.5
16.7
Table 6. Select Function for Data Byte 0, Bits 0:1
Input Conditions
Output Conditions
Data Byte 0
Function
Bit 1
Bit 0
CPU0:2,
PCI0:9
REF2X
IOAPIC0:2
48/24MHZ
Normal Operation
0
0
Note 2
Note 2
14.318 MHz
Note 2
48/24 MHz
Test Mode
0
1
TBD
TBD
TBD
TBD
TBD
Spread Spectrum
1
0
±0.25%
±0.25%
14.318 MHz
±0.25%
48/24 MHz
Three-state
1
1
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Note:
2. CPU, IOAPIC, and PCI frequency selections are listed in Table 1 and Table 5.
9
PRELIMINARY
W167B
Although the W167B is a receive-only device (no data writeback capability), it does transmit an “acknowledge” data pulse
after each byte is received. Thus, the SDATA line can both
transmit and receive data.
How To Use the Serial Data Interface
Electrical Requirements
Figure 5 illustrates electrical characteristics for the serial interface bus used with the W167B. Devices send data over the bus
with an open drain logic output that can (a) pull the bus line
LOW, or (b) let the bus default to logic 1. The pull-up resistors
on the bus (both clock and data lines) establish a default logic
1. All bus devices generally have logic inputs to receive data.
The pull-up resistor should be sized to meet the rise and fall
times specified in AC parameters, taking into consideration total bus line capacitance.
VDD
VDD
~ 2kΩ
~ 2kΩ
SERIAL BUS DATA LINE
SERIAL BUS CLOCK LINE
SDCLK
CLOCK IN
CLOCK OUT
SDATA
SCLOCK
DATA IN
N
DATA OUT
CLOCK IN
N
DATA IN
DATA OUT
CHIP SET
(SERIAL BUS MASTER TRANSMITTER)
CLOCK DEVICE
(SERIAL BUS SLAVE RECEIVER)
Figure 5. Serial Interface Bus Electrical Characteristics
10
SDATA
N
PRELIMINARY
W167B
Signaling Requirements
Sending Data to the W167B
As shown in Figure 6, valid data bits are defined as stable logic
0 or 1 condition on the data line during a clock HIGH (logic 1)
pulse. A transitioning data line during a clock HIGH pulse may
be interpreted as a start or stop pulse (it will be interpreted as
a start or stop pulse if the start/stop timing parameters are
met).
The device accepts data once it has detected a valid start bit
and address byte sequence. Device functionality is changed
upon the receipt of each data bit (registers are not double buffered). Partial transmission is allowed meaning that a transmission can be truncated as soon as the desired data bits are
transmitted (remaining registers will be unmodified). Transmission is truncated with either a stop bit or new start bit (restart
condition).
A write sequence is initiated by a “start bit” as shown in Figure
7. A “stop bit” signifies that a transmission has ended.
As stated previously, the W167B sends an “acknowledge”
pulse after receiving eight data bits in each byte as shown in
Figure 8.
SDATA
SCLOCK
Valid
Data
Bit
Change
of Data Allowed
Figure 6. Serial Data Bus Valid Data Bit
SDATA
SCLOCK
Start
Bit
Stop
Bit
Figure 7. Serial Data Bus Start and Stop Bit
11
Stop Condition
Slave Address
(First Byte)
Command Code
(Second Byte)
SDATA
MSB
1
1
0
1
0
0
LSB
1
0
SCLOCK
1
2
3
4
5
6
7
8
Byte Count
(Third Byte)
MSB
A
1
LSB
2
3
4
5
6
7
8
Last Data Byte
(Last Byte)
MSB
A
1
MSB
2
3
4
1
LSB
2
3
4
5
6
SDATA
Acknowledgment Bit
from Clock Device
Signaling by Clock Device
7
8
A
PRELIMINARY
Figure 8. Serial Data Bus Write Sequence
Signaling from System Core Logic
Start Condition
12
tSPF
tLOW
SCLOCK
tSTHD
tDSU
tHIGH
tR
tF
tDHD
tSP
tSPSU
tSTHD
t SPSU
W167B
Figure 9. Serial Data Bus Timing Diagram
SDATA
PRELIMINARY
W167B
Absolute Maximum Ratings
above those specified in the operating sections of this specification is not implied. Maximum conditions for extended periods may affect reliability.
Stresses greater than those listed in this table may cause permanent damage to the device. These represent a stress rating
only. Operation of the device at these or any other conditions
.
Parameter
Description
Rating
Unit
V
VDD, VIN
Voltage on any pin with respect to GND
–0.5 to +7.0
–65 to +150
°C
0 to +70
°C
–55 to +125
°C
2 (min.)
kV
TSTG
Storage Temperature
TA
Operating Temperature
TB
Ambient Temperature under Bias
ESDPROT
Input ESD Protection
DC Electrical Characteristics: TA = 0°C to +70°C, VDDQ3 = 3.3V±5%, VDDQ2 = 2.5V±5%
Parameter
Description
Test Condition
Min.
Typ.
Max.
Unit
160
mA
90
mA
Supply Current
IDD-3.3V
IDD-2.5
Combined 3.3V Supply Current
CPU0:3 =133 MHz[3]
Combined 2.5V Supply Current
[3]
CPU0:3 =133 MHz
Logic Inputs (All referenced to VDDQ3 = 3.3V)
VIL
Input Low Voltage
GND –
0.3
0.8
V
VIH
Input High Voltage
2.0
VDD +
0.3
V
IIL
Input Low Current[4]
–25
µA
10
µA
IIH
[4]
Input High Current
[4]
IIL
Input Low Current, SEL133/100#
–5
µA
IIH
Input High Current, SEL133/100#[4]
5
µA
Max.
Unit
50
mV
Clock Outputs
CPU, CPUdiv2, IOAPIC (Referenced to VDDQ2)
Test Condition
Min.
Typ.
VOL
Output Low Voltage
IOL = 1 mA
VOH
Output High Voltage
IOH = –1 mA
2.2
IOL
Output Low Current
VOL = 1.25V
45
65
100
mA
IOH
Output High Current
VOH = 1.25V
45
65
100
mA
Min.
Typ.
Max.
Unit
50
mV
48MHz, REF (Referenced to VDDQ3)
Test Condition
VOL
Output Low Voltage
IOL = 1 mA
VOH
Output High Voltage
IOH = –1 mA
3.1
IOL
Output Low Current
VOL = 1.5V
45
IOH
Output High Current
VOH = 1.5V
PCI, 3V66 (Referenced to VDDQ3)
Test Condition
V
V
65
100
mA
45
65
100
mA
Min.
Typ.
Max.
Unit
50
mV
VOL
Output Low Voltage
IOL = 1 mA
VOH
Output High Voltage
IOH = –1 mA
3.1
IOL
Output Low Current
VOL = 1.5V
70
100
145
mA
IOH
Output High Current
VOH = 1.5V
65
95
135
mA
Notes:
3. All clock outputs loaded with 6" 60Ω transmission lines with 20-pF capacitors.
4. W167B logic inputs have internal pull-up devices, except SEL133/100# (pull-ups not CMOS level).
13
V
PRELIMINARY
W167B
DC Electrical Characteristics: TA = 0°C to +70°C, VDDQ3 = 3.3V±5%, VDDQ2 = 2.5V±5% (continued)
Parameter
Description
Test Condition
Min.
Typ.
Max.
Unit
Crystal Oscillator
VTH
X1 Input Threshold Voltage[5]
CLOAD
Load Capacitance, Imposed on
External Crystal[6]
CIN,X1
X1 Input Capacitance[7]
Pin X2 unconnected
1.65
V
18
pF
28
pF
Pin Capacitance/Inductance
CIN
Input Pin Capacitance
COUT
Output Pin Capacitance
6
pF
LIN
Input Pin Inductance
7
nH
Except X1 and X2
5
pF
3.3V AC Electrical Characteristics
TA = 0°C to +70°C, VDDQ3 = 3.3V±5%,VDDQ2 = 2.5V± 5% fXTL = 14.31818 MHz
Spread Spectrum function turned off
AC clock parameters are tested and guaranteed over stated operating conditions using the stated lump capacitive load at the
clock output.[8]
3V66 Clock Outputs, 3V66_0:2 (Lump Capacitance Test Load = 30 pF)
Parameter
Description
Test Condition/Comments
Min.
Typ.
Max.
66.6
Unit
f
Frequency
Note 9
tR
Output Rise Edge Rate
Measured from 0.4V to 2.4V
1
4
V/ns
tF
Output Fall Edge Rate
Measured from 2.4V to 0.4V
1
4
V/ns
tD
Duty Cycle
Measured on rising and falling edge at 1.5V
45
55
%
fST
Frequency Stabilization
from Power-up (cold start)
Assumes full supply voltage reached within
1 ms from power-up. Short cycles exist prior
to frequency stabilization.
3
ms
Zo
AC Output Impedance
Average value during switching transition.
Used for determining series termination
value.
15
MHz
Ω
Notes:
5. X1 input threshold voltage (typical) is VDD/2.
6. The W167B contains an internal crystal load capacitor between pin X1 and ground and another between pin X2 and ground. Total load placed on crystal is
18 pF; this includes typical stray capacitance of short PCB traces to crystal.
7. X1 input capacitance is applicable when driving X1 with an external clock source (X2 is left unconnected).
8. Period, jitter, offset, and skew measured on rising edge at 1.5V.
9. 3V66 is CPU/2 for CPU =133 MHz and (2 x CPU)/3 for CPU = 100 MHz.
14
PRELIMINARY
W167B
PCI Clock Outputs, PCI0:9 (Lump Capacitance Test Load = 30 pF
Parameter
Description
Test Condition/Comments
[10]
Min.
Typ.
Max.
Unit
tP
Period
Measured on rising edge at 1.5V
30
ns
tH
High Time
Duration of clock cycle above 2.4V
12
ns
tL
Low Time
Duration of clock cycle below 0.4V
12
ns
tR
Output Rise Edge Rate
Measured from 0.4V to 2.4V
1
tF
Output Fall Edge Rate
Measured from 2.4V to 0.4V
tD
Duty Cycle
Measured on rising and falling edge at 1.5V
tJC
Jitter, Cycle-to-Cycle
tSK
4
V/ns
1
4
V/ns
45
55
%
Measured on rising edge at 1.5V. Maximum
difference of cycle time between two adjacent cycles.
500
ps
Output Skew
Measured on rising edge at 1.5V
500
ps
tO
3V66 to PCI Clock Skew
Covers all 3V66/PCI outputs. Measured on rising
edge at 1.5V. 3V66 leads PCI output.
4
ns
fST
Frequency Stabilization
from Power-up (cold
start)
Assumes full supply voltage reached within 1 ms
from power-up. Short cycles exist prior to frequency
stabilization.
3
ms
Zo
AC Output Impedance
Average value during switching transition. Used for
determining series termination value.
1.5
Ω
15
REF Clock Outputs, REF0:1 (Lump Capacitance Test Load = 20 pF)
Parameter
Description
Test Condition/Comments
Min.
Typ.
Max.
Unit
f
Frequency, Actual
Frequency generated by crystal oscillator
14.318
tR
Output Rise Edge Rate
Measured from 0.4V to 2.4V
0.5
2
V/ns
tF
Output Fall Edge Rate
Measured from 2.4V to 0.4V
0.5
2
V/ns
tD
Duty Cycle
Measured on rising and falling edge at 1.5V
45
55
%
fST
Frequency Stabilization from
Power-up (cold start)
Assumes full supply voltage reached within
1 ms from power-up. Short cycles exist prior to
frequency stabilization.
3
ms
Zo
AC Output Impedance
Average value during switching transition. Used
for determining series termination value.
Ω
25
48-MHZ Clock Output (Lump Capacitance Test Load = 20 pF)
Parameter
Description
Test Condition/Comments
Min.
Typ.
Max.
Unit
f
Frequency, Actual
Determined by PLL divider ratio (see m/n below)
fD
Deviation from 48 MHz
(48.008 – 48)/48
m/n
PLL Ratio
(14.31818 MHz x 57/17 = 48.008 MHz)
tR
Output Rise Edge Rate
Measured from 0.4V to 2.4V
0.5
2
V/ns
tF
Output Fall Edge Rate
Measured from 2.4V to 0.4V
0.5
2
V/ns
tD
Duty Cycle
Measured on rising and falling edge at 1.5V
45
55
%
fST
Frequency Stabilization
from Power-up (cold start)
Assumes full supply voltage reached within 1 ms
from power-up. Short cycles exist prior to frequency stabilization.
3
ms
Zo
AC Output Impedance
Average value during switching transition. Used
for determining series termination value.
Note:
10. PCI clock is CPU/4 for CPU = 133 MHz and CPU/3 for CPU = 100 MHz.
15
48.008
MHz
+167
ppm
57/17
25
Ω
PRELIMINARY
W167B
2.5V AC Electrical Characteristics
TA = 0°C to +70°C, VDDQ3 = 3.3V±5%, V DDQ2= 2.5V±5%
fXTL = 14.31818 MHz
Spread Spectrum function turned off
AC clock parameters are tested and guaranteed over stated operating conditions using the stated lump capacitive load at the
clock output.[11]
CPU Clock Outputs, CPU0:2 (Lump Capacitance Test Load = 20 pF)
CPU = 133 MHz
Parameter
Description
Test Condition/Comments
CPU = 100 MHz
Min. Typ. Max. Min.
Typ. Max. Unit
tP
Period
Measured on rising edge at 1.25V
7.5
tH
High Time
Duration of clock cycle above 2.0V
1.87
3.0
ns
tL
Low Time
Duration of clock cycle below 0.4V
1.67
2.8
ns
tR
Output Rise Edge Rate Measured from 0.4V to 2.0V
1
4
1
4
V/ns
tF
Output Fall Edge Rate
Measured from 2.0V to 0.4V
1
4
1
4
V/ns
tD
Duty Cycle
Measured on rising and falling edge at
1.25V
45
55
45
55
%
tJC
Jitter, Cycle-to-Cycle
Measured on rising edge at 1.25V. Maximum difference of cycle time between
two adjacent cycles.
250
250
ps
tSK
Output Skew
Measured on rising edge at 1.25V
175
175
ps
fST
Frequency Stabilization from Power-up
(cold start)
Assumes full supply voltage reached
within 1 ms from power-up. Short cycles
exist prior to frequency stabilization.
3
3
ms
Zo
AC Output Impedance
Average value during switching transition. Used for determining series termination value.
7.65
10
10.2
ns
Ω
20
20
CPU = 133 MHz
CPU = 100 MHz
CPUdiv2 Clock Outputs, CPUdiv2 (Lump Capacitance Test Load = 20 pF)
Parameter
Description
Test Condition/Comments
Min. Typ. Max. Min.
Measured on rising edge at 1.25V
15
tH
High Time
Duration of clock cycle above 2.0V
5.25
7.5
ns
tL
Low Time
Duration of clock cycle below 0.4V
5.05
7.3
ns
tR
Output Rise Edge Rate Measured from 0.4V to 2.0V
1
4
1
4
V/ns
tF
Output Fall Edge Rate
Measured from 2.0V to 0.4V
1
4
1
4
V/ns
tD
Duty Cycle
Measured on rising and falling edge at
1.25V
45
55
45
55
%
tJC
Jitter, Cycle-to-Cycle
Measured on rising edge at 1.25V. Maximum difference of cycle time between
two adjacent cycles.
250
250
ps
tSK
Output Skew
Measured on rising edge at 1.25V
175
175
ps
fST
Frequency Stabilization from Power-up
(cold start)
Assumes full supply voltage reached
within 1 ms from power-up. Short cycles
exist prior to frequency stabilization.
3
3
ms
Zo
AC Output Impedance
Average value during switching transition. Used for determining series termination value.
16
20
20
20.4
Unit
Period
Note:
11. Period, Jitter, offset, and skew measured on rising edge at 1.25V.
15.3
Typ. Max.
tP
20
ns
Ω
PRELIMINARY
W167B
IOAPIC Clock Output, IOAPIC (Lump Capacitance Test Load = 20 pF)
Parameter
Description
Test Condition/Comments
f
Frequency
Note 12
tR
Output Rise Edge Rate
Measured from 0.4V to 2.0V
tF
Output Fall Edge Rate
Measured from 2.0V to 0.4V
tD
Duty Cycle
Measured on rising and falling edge at 1.25V
fST
Frequency Stabilization
from Power-up (cold start)
Assumes full supply voltage reached within
1 ms from power-up. Short cycles exist prior to
frequency stabilization.
Zo
AC Output Impedance
Average value during switching transition. Used
for determining series termination value.
Ordering Information
W167B
Package
Name
H
Typ
Max
16.67
Note:
12. IOAPIC clock is CPU/8 for CPU = 133 MHz and CPU/6 for CPU = 100 MHz.
Ordering Code
Min
Package Type
48-pin SSOP (300 mils)
Document #: 38-00816
17
1
Unit
MHz
4
V/ns
1
4
V/ns
45
55
%
3
ms
20
Ω
PRELIMINARY
W167B
Package Diagram
48-Pin Small Shrink Outline Package (SSOP, 300 mils)
© Cypress Semiconductor Corporation, 1999. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use
of any circuitry other than circuitry embodied in a Cypress Semiconductor product. Nor does it convey or imply any license under patent or other rights. Cypress Semiconductor does not authorize
its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress
Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.