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W149
440BX AGPset Spread Spectrum Frequency Synthesizer
Features
* Maximized EMI suppression using Cypress's Spread Spectrum Technology * Single chip system frequency synthesizer for Intel(R) 440BX AGPset * Two copies of CPU output * Six copies of PCI output * One 48-MHz output for USB * One 24-MHz output for SIO * Two buffered reference outputs * One IOAPIC output * Thirteen SDRAM outputs provide support for 3 DIMMs * Spread Spectrum feature always enabled * I2CTM interface for programming * Power management control inputs * Smooth CPU frequency switching from 66.8-124 MHz VDDQ3: ..................................................................... 3.3V5% VDDQ2: ..................................................................... 2.5V5% SDRAMIN to SDRAM0:12 Delay:.......................... 3.7 ns typ. Table 1. Mode Input Table[1] Mode 0 1 Table 2. Pin Selectable Frequency Input Address FS2 1 1 1 1 0 0 0 0 FS1 1 1 0 0 1 1 0 0 FS0 1 0 1 0 1 0 1 0
[2]
Pin 2 PCI_STOP# REF0
CPU0:1 (MHz) 100 100 103 66.8 83.3 66.8 124
PCI_F, 1:5 (MHz) 33.3 (CPU/3) (Reserved) 33.3 (CPU/3) 34.3 (CPU/3) 33.4 (CPU/2) 41.7 (CPU/2) 33.4 (CPU/2) 41.3 (CPU/3)
Spread % -0.5 0.5 -0.5 -0.5 -0.5 0.5 -0.5
Key Specifications
CPU Cycle-to-Cycle Jitter: ......................................... 250 ps CPU to CPU Output Skew: ........................................ 175 ps PCI to PCI Output Skew: ............................................ 500 ps
Logic Block Diagram
VDDQ3 REF0/(PCI_STOP#) X1 X2 XTAL OSC
PLL Ref Freq
Pin Configuration
REF1/FS2
VDDQ2
I/O Pin Control
IOAPIC
VDDQ2 CPU0 PLL 1 /2//3 CPU1 VDDQ3 PCI_F/MODE PCI1 PCI2 PCI3 PCI4
SDATA SCLK
Stop Clock Control
VDDQ3 REF0/(PCI_STOP#) GND X1 X2 VDDQ3 PCI_F/MODE PCI1 GND PCI2 PCI3 PCI4 PCI5 VDDQ3 SDRAMIN GND SDRAM11 SDRAM10 VDDQ3 SDRAM9 SDRAM8 GND 2 SDAT A IC SCLK
{
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25
VDDQ2 IOAPIC REF1/FS2* GND CPU0 CPU1 VDDQ2 OE SDRAM12 GND SDRAM0 SDRAM1 VDDQ3 SDRAM2 SDRAM3 GND SDRAM4 SDRAM5 VDDQ3 SDRAM6 SDRAM7 VDDQ3 48MHz/FS0* 24MHz/FS1*
W149
I2C Logic
PCI5
PLL2
/2
VDDQ3 48MHz/FS0
SDRAMIN
24MHz/FS1 VDDQ3 SDRAM0:12 13
Intel is a registered trademark of Intel Corporation. I2C is a trademark of Philips Corporation. Notes: 1. Mode input latched at power-up. 2. Internal pull up resistors(*) should not be relied upon for setting I/O pins HIGH. Pin function with parentheses determined by MODE pin resistor strapping.
Cypress Semiconductor Corporation
*
3901 North First Street
*
San Jose
*
CA 95134
* 408-943-2600 July 31, 2000 rev. *A
W149
Pin Definitions
Pin Name CPU0:1 PCI1:5 Pin No. 44, 43 8, 10, 11, 12, 13 7 Pin Type O O Pin Description CPU Clock Outputs: See Tables 2 and 6 for detailed frequency information. Output voltage swing is controlled by voltage applied to VDDQ2. PCI Clock Outputs 1 through 5: These five PCI clock outputs are controlled by the PCI_STOP# control pin. Output voltage swing is controlled by voltage applied to VDDQ3. Fixed PCI Clock Output: Frequency is set by the FS0:1 inputs or through serial input interface, see Tables 2 and 6. This output is not affected by the PCI_STOP# input. Upon power-up the mode input will be latched, which will determine the function of pin 2, REF0/(PCI_STOP#). See Table 1. Output Enable Input: When brought LOW, all outputs are placed in a high-impedance state. When brought HIGH, all clock outputs activate. IOAPIC Clock Output: Provides 14.318-MHz fixed frequency. The output voltage swing is controlled by VDDQ2. 48-MHz Output: 48 MHz is provided in normal operation. In standard systems, this output can be used as the reference for the Universal Serial Bus. Upon power-up, FS0 input will be latched, which will set clock frequencies as described in Table 2. This output does not have the Spread Spectrum feature. 24-MHz Output: 24 MHz is provided in normal operation. In standard systems, this output can be used as the clock input for a Super I/O chip. Upon power-up FS1 input will be latched, which will set clock frequencies as described in Table 2. This output does not have the Spread Spectrum feature. I/O Dual-Function REF1 and FS2 pin: Upon power-up, FS2 input will be latched which will set clock frequencies as described in Table 2. When an output, this pin provides a fixed clock signal equal in frequency to the reference signal provided at the X1/X2 pins. Fixed 14.318-MHz Output 0 or PCI_STOP# Pin: Function is determined by the MODE input. When set as an input, the PCI_STOP# input enables the PCI 1:5 outputs when HIGH and causes them to remain at logic 0 when LOW. The PCI_STOP signal is latched on the rising edge of PCI_F. Its effects take place on the next PCI_F clock cycle. When an output, this pin provides a fixed clock signal equal in frequency to the reference signal provided at the X1/X2 pins. Buffered Input Pin: The signal provided to this input pin is buffered to 13 outputs (SDRAM0:12). Buffered Outputs: These thirteen dedicated outputs provide copies of the signal provided at the SDRAMIN input. The swing is set by VDDQ3, and they are deactivated when CLK_STOP# input is set LOW. Clock pin for I2C circuitry. Data pin for I2C circuitry. 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: An input connection for an external 14.318-MHz crystal. If using an external reference, this pin must be left unconnected. Power Connection: Power supply for core logic, PLL circuitry, SDRAM outputs, PCI outputs, reference outputs, 48-MHz output, and 24-MHz output. Connect to 3.3V supply. Power Connection: Power supply for IOAPIC and CPU0:1 output buffers. Connect to 2.5V, or 3.3V. Ground Connections: Connect all ground pins to the common system ground plane.
PCI_F/MODE
I/O
OE IOAPIC 48MHz/FS0
41 47 26
I O I/O
24MHz/FS1
25
I/O
REF1/FS2
46
I/O
REF0/ (PCI_STOP#)
2
I/O
SDRAMIN SDRAM0:12
15 38, 37, 35, 34, 32, 31, 29, 28, 21, 20, 18, 17, 40 24 23 4
I
O
SCLK SDATA X1
I I/O I
X2 VDDQ3
5 1, 6, 14, 19, 27, 30, 36 42, 48 3, 9, 16, 22, 33, 39, 45
I P
VDDQ2 GND
P G
2
W149
Overview
The W149 was developed as a single chip device to meet the clocking needs of the Intel 440BX AGPset. In addition to the typical outputs provided by standard 100-MHz 440BX AGPset FTGs, the W149 adds a thirteen output buffer, supporting SDRAM DIMM modules in conjunction with the chipset. Cypress proprietary spread spectrum frequency synthesis technique is a feature of the CPU and PCI outputs. This feature reduces the peak EMI measurements of not only the output signals and their harmonics, but also of any other clock signals that are properly synchronized to them. Upon W149 power-up, the first 2 ms of operation is used for input logic selection. During this period, the four I/O pins (7, 25, 26, 46) are three-stated, allowing the output strapping resistor on the l/O pins to pull each 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 the l/O pin is latched. Next the output buffer is 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. It should be noted that the strapping resistors have no significant effect on clock output signal integrity. The drive impedance of clock output is <40 (nominal), which is minimally affected by the 10-k 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. When the clock outputs are enabled following the 2-ms input period, the specified output frequency is delivered on the pin, 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.
Functional Description
I/O Pin Operation Pins 7, 25, 26, 46 are dual-purpose l/O pins. Upon power-up these pins act as logic inputs, allowing the determination of assigned device functions. A short time after power-up, the logic state of each pin is latched and the pins become clock outputs. This feature reduces device pin count by combining clock outputs with input select pins. An external 10-k "strapping" resistor is connected between the l/O pin and ground or VDD. Connection to ground sets a latch to "0", connection to VDD sets a latch to "1". Figure 1 and Figure 2 show two suggested methods for strapping resistor connections.
VDD
2XWSXW 6WUDSSLQJ 5HVLVWRU 6HULHV 7HUP LQDWLRQ 5HVLVWRU
10 k
/RDG 2SWLRQ
W149 Power-on Reset Timer
Clock Load Output Buffer Output Three-state
Q
Hold Output Low
D
10 k
/RDG 2SWLRQ
Data Latch
Figure 1. Input Logic Selection Through Resistor Load Option
Jumper Options Output Strapping Resistor Series Termination Resistor 10 k W149 Power-on Reset Timer Output Buffer Output Three-state Hold Output Low
Q D
VDD
R Resistor Value R
Clock Load
Data Latch
Figure 2. Input Logic Selection Through Jumper Option
3
W149
Spread Spectrum Clocking
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. 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) Where ! is the percentage of deviation and is the frequency in MHz where the reduction is measured. 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 either -0.5% or 0.5% of the selected frequency. 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. Spread Spectrum clocking cannot be deactivated on the W149.
SSFTG
Typical Clock
Amplitude (dB)
Frequency Span (MHz) Center Spread
Figure 3. Clock Harmonic with and without SSCG Modulation Frequency Domain Representation
MAX (+0.5%)
FREQUENCY
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
10%
20%
30%
40%
50%
60%
70%
80%
90%
MIN (-0.5%)
Figure 4. Typical Modulation Profile
4
100%
W149
Serial Data Interface
The W149 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 W149 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 SDATA and SCLOCK. In motherboard applications, SDATA and SCLOCK are typically driven by two logic outputs of the Table 3. Serial Data Interface Control Functions Summary Control Function Clock Output Disable Description Any individual clock output(s) can be disabled. Disabled outputs are actively held LOW. Provides CPU/PCI frequency selections through software. Frequency is changed in a smooth and controlled fashion. Puts clock output into a high-impedance state. Reserved function for future device revision or production device testing. Common Application Unused outputs are disabled to reduce EMI and system power. Examples are clock outputs to unused PCI slots. For alternate microprocessors and power management options. Smooth frequency transition allows CPU frequency change under normal system operation. Production PCB testing. No user application. Register bit must be written as 0. 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 3 summarizes the control functions of the serial data interface. Operation Data is written to the W149 in eleven bytes of eight bits each. Bytes are written in the order shown in Table 4.
CPU Clock Frequency Selection
Output Three-state (Reserved)
Table 4. Byte Writing Sequence Byte Sequence 1 Byte Name Slave Address Bit Sequence 11010010 Byte Description Commands the W149 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 W149 is 11010010. Register setting will not be made if the Slave Address is not correct (or is for an alternate slave receiver). Unused by the W149, 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. Unused by the W149, 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. The data bits in Data Bytes 0-7 set internal W149 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 5, Data Byte Serial Configuration Map.
2
Command Code
Don't Care
3
Byte Count
Don't Care
4 5 6 7 8 9 10 11
Data Byte 0 Data Byte 1 Data Byte 2 Data Byte 3 Data Byte 4 Data Byte 5 Data Byte 6 Data Byte 7
Refer to Table 5
5
W149
Writing Data Bytes Each bit in Data Bytes 0-7 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 7. Table 5 gives the bit formats for registers located in Data Bytes 0-7. Table 5. Data Bytes 0-7 Serial Configuration Map Affected Pin Bit(s) 7 6 5 4 3 2 1-0 Pin No. -------Pin Name -------Don't Care SEL_2 SEL_1 SEL_0 Hardware/Software Frequency Select Don't Care Bit 1 0 0 1 1 Bit 0 0 1 0 1 -Function (See Table 7 for function details) Normal Operation (Reserved) Normal Operation All Outputs Three-stated ----Low -Low Low -Low -Low Low Low Low Low --Low Low -Low ----Active -Active Active -Active -Active Active Active Active Active --Active Active -Active Control Function 0 -See Table 6 See Table 6 See Table 6 Hardware Software -Data Byte 0 -0 0 0 0 0 0 00 Bit Control 1 Default Table 6 details additional frequency selections that are available through the serial data interface. Table 7 details the select functions for Byte 0, bits 1 and 0.
Data Byte 1 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 Data Byte 3 7 6 5 4 3 2 --26 25 -21, 20, 18, 17 --48MHz 24MHz -SDRAM8:11 (Reserved) (Reserved) Clock Output Disable Clock Output Disable (Reserved) Clock Output Disable 0 0 1 1 0 1 ----40 -43 44 -7 -13 12 11 10 8 ----SDRAM12 -CPU1 CPU0 -PCI_F -PCI5 PCI4 PCI3 PCI2 PCI1 (Reserved) (Reserved) (Reserved) (Reserved) Clock Output Disable (Reserved) Clock Output Disable Clock Output Disable (Reserved) Clock Output Disable (Reserved) Clock Output Disable Clock Output Disable Clock Output Disable Clock Output Disable Clock Output Disable 0 0 0 0 1 0 1 1 0 1 0 1 1 1 1 1
Data Byte 2
6
W149
Table 5. Data Bytes 0-7 Serial Configuration Map (continued) Affected Pin Bit(s) 1 0 Pin No. 32, 31, 29, 28 38, 37, 35, 34 -----------47 --46 2 ----------------Pin Name SDRAM4:7 SDRAM0:3 Control Function Clock Output Disable Clock Output Disable 0 Low Low Bit Control 1 Active Active Default 1 1
Data Byte 4 7 6 5 4 3 2 1 0 Data Byte 5 7 6 5 4 3 2 1 0 Data Byte 6 7 6 5 4 3 2 1 0 Data Byte 7 7 6 5 4 3 2 1 0 --------(Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) ----------------0 0 0 0 0 0 0 0 --------(Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) ----------------0 0 0 0 0 0 0 0 ---IOAPIC --REF1 REF0 (Reserved) (Reserved) (Reserved) Clock Output Disable (Reserved) (Reserved) Clock Output Disable Clock Output Disable ---Low --Low Low ---Active --Active Active 0 0 0 1 0 0 1 1 --------(Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) ----------------0 0 0 0 0 0 0 0
7
W149
Table 6. Additional Frequency Selections through Serial Data Interface Data Bytes[3] Input Conditions Data Byte 0, Bit 3 = 1 Bit 6 SEL_2 1 1 1 1 0 0 0 0 Bit 5 SEL_1 1 1 0 0 1 1 0 0 Bit 4 SEL_0 1 0 1 0 1 0 1 0 CPU0:1, SDRAM0:12 (MHz) 100. 2 (Reserved) 100 103 66.8 83.3 66.8 124 PCI_F, 1:5 (MHz) 33.4 (Reserved) 33.3 34.3 33.4 41.65 33.4 41.3 -0.5 (Reserved) 0.5 -0.5 -0.5 -0.5 0.5 -0.5 Output Frequency Spread %
Table 7. Select Function for Data Byte 0, Bits 0:1 Input Conditions Data Byte 0 Function Normal Operation Three-state Bit 1 X 1 Bit 0 0 1 CPU0:1 Note 1 Hi-Z PCI_F, PCI1:5 Note 1 Hi-Z Output Conditions REF0:1, IOAPIC 14.318 MHz Hi-Z 48MHZ 48 MHz Hi-Z 24MHZ 24 MHz Hi-Z
Note: 3. CPU and PCI frequency selections are listed in Table 2 and Table 6.
8
W149
Absolute Maximum Ratings
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
.
above those specified in the operating sections of this specification is not implied. Maximum conditions for extended periods may affect reliability. Rating -0.5 to +7.0 -65 to +150 -55 to +125 0 to +70 2 (min) Unit V C C C kV
Parameter VDD, VIN TSTG TB TA ESDPROT
Description Voltage on any pin with respect to GND Storage Temperature Ambient Temperature under Bias Operating Temperature Input ESD Protection
DC Electrical Characteristics: TA = 0C to +70C; VDDQ3 = 3.3V5%; VDDQ2 = 2.5V5%
Parameter Supply Current IDD IDD Logic Inputs VIL VIH IIL IIH VOL VOH VOH IOL Input Low Voltage Input High Voltage Input Low Current[5] Input High Current[5] Output Low Voltage Output High Voltage Output High Voltage Output Low Current CPU0:1, IOAPIC CPU0:1 PCI_F, PCI1:5 IOAPIC REF0:1 48MHz 24MHz IOH IOH Output High Current Output High Current CPU0:1 PCI_F, PCI1:5 IOAPIC REF0:1 48MHz 24MHz IOL = 1 mA IOH = 1 mA IOH = -1 mA VOL = 1.25V VOL = 1.5V VOL = 1.25V VOL = 1.5V VOL = 1.5V VOL = 1.5V VOH = 1.25V VOH = 1.5V VOH = 1.25V VOH = 1.5V VOH = 1.5V VOH = 1.5V 3.1 2.2 27 20.5 40 25 25 25 25 31 40 27 27 25 57 53 85 37 37 37 55 55 87 44 44 37 97 139 140 76 76 76 97 139 155 94 94 76 GND - 0.3 2.0 0.8 VDD + 0.3 -25 10 50 V V A A mV V V mA mA mA mA mA mA mA mA mA mA mA mA 3.3V Supply Current 2.5V Supply Current CPU0:1 = 100 MHz Outputs Loaded [4] CPU0:1 = 100 MHz Outputs Loaded [4] 260 25 mA mA Description Test Condition Min. Typ. Max. Unit
Clock Outputs
Notes: 4. All clock outputs loaded with 6" 60 traces with 22-pF capacitors. 5. W149 logic inputs have internal pull-up devices (pull-ups not full CMOS level).
9
W149
DC Electrical Characteristics: (continued) TA = 0C to +70C; VDDQ3 = 3.3V5%; VDDQ2 = 2.5V5%
Parameter Crystal Oscillator VTH CLOAD CIN,X1 CIN COUT LIN X1 Input threshold Voltage[6] Load Capacitance, Imposed on External Crystal[7] X1 Input Capacitance[8] Input Pin Capacitance Output Pin Capacitance Input Pin Inductance Pin X2 unconnected Except X1 and X2 VDDQ3 = 3.3V 1.65 14 28 5 6 7 V pF pF pF pF nH Description Test Condition Min. Typ. Max. Unit
Pin Capacitance/Inductance
Notes: 6. X1 input threshold voltage (typical) is VDDQ3 /2. 7. The W149 contains an internal crystal load capacitor between pin X1 and ground and another between pin X2 and ground. Total load placed on crystal is 14 pF; this includes typical stray capacitance of short PCB traces to crystal. 8. X1 input capacitance is applicable when driving X1 with an external clock source (X2 is left unconnected).
AC Electrical Characteristics
TA = 0C to +70C; VDDQ3 = 3.3V5%; VDDQ2 = 2.5V5%; fXTL = 14.31818 MHz AC clock parameters are tested and guaranteed over stated operating conditions using the stated lump capacitive load at the clock output; Spread Spectrum clocking is disabled. CPU Clock Outputs, CPU_F, CPU1 (Lump Capacitance Test Load = 20 pF) CPU = 66.6 MHz Parameter tP tH tL tR tF tD tJC Description Period High Time Low Time Test Condition/Comments Measured on rising edge at 1.25V Duration of clock cycle above 2.4V, at min. edge rate (1.5 V/ns) Duration of clock cycle below 0.4V, at min. edge rate (1.5 V/ns) Measured from 2.4V to 0.4V Measured on rising and falling edge at 1.5V, at min. edge rate (1.5 V/ns) Measured on rising edge at 1.25V. Maximum difference of cycle time between two adjacent cycles. Measured on rising edge at 1.5V Assumes full supply voltage reached within 1 ms from power-up. Short cycles exist prior to frequency stabilization. Average value during switching transition. Used for determining series termination value. 20 15 5.6 5.3 1.5 1.5 45 4 4 55 200 15.5 CPU = 100 MHz 10 3.3 3.1 1.5 1.5 45 4 4 55 200 10.5 ns ns ns V/ns V/ns % ps Min. Typ. Max. Min. Typ. Max. Unit
Output Rise Edge Rate Measured from 0.4V to 2.4V Output Fall Edge Rate Duty Cycle Jitter, Cycle-to-Cycle
tSK fST
Output Skew Frequency Stabilization from Power-up (cold start) AC Output Impedance
250 3
250 3
ps ms
Zo
20
10
W149
SDRAM Clock Outputs, SDRAM, SDRAM0:11 (Lump Capacitance Test Load = 30 pF) CPU = 66.6 MHz Parameter tP tH tL tR tF tPLH tPHL tD Description Period High Time Low Time Output Rise Edge Rate Output Fall Edge Rate Prop Delay LH Prop Delay HL Duty Cycle Test Condition/Comments Measured on rising edge at 1.5V Duration of clock cycle above 2.4V, at min. sdge rate (1.5 V/ns) Duration of clock cycle below 0.4V, at min. sdge rate (1.5 V/ns) Measured from 0.4V to 2.4V Measured from 2.4V to 0.4V Input edge rate faster than 1 V/ns Input edge rate faster than 1 V/ns Measured on rising and falling edge at 1.5V, at min. sdge rate (1.5 V/ns) Measured on rising edge at 1.5V. Maximum difference of cycle time between two adjacent cycles. Measured on rising edge at 1.5V Covers all CPU/PCI outputs. Measured on rising edge at 1.5V. CPU leads PCI output. Assumes full supply voltage reached within 1 ms from power-up. Short cycles exist prior to frequency stabilization. Average value during switching transition. Used for determining series termination value. 30 1.5 Min. 30 5.6 5.3 1.5 1.5 1 1 45 4 4 5 5 55 Typ. Max. CPU = 100 MHz Min. 30 3.3 3.1 1.5 1.5 1 1 45 4 4 5 5 55 Typ. Max. Unit ns ns ns V/ns V/ns ns ns %
tJC
Jitter, Cycle-to-Cycle
250
250
ps
tSK tO
Output Skew CPU to PCI Clock Skew Frequency Stabilization from Power-up (cold start) AC Output Impedance
250 4 1.5
250 4
ps ns
fST
3
3
ms
Zo
30
11
W149
PCI Clock Outputs, PCI_F and PCI1:5 (Lump Capacitance Test Load = 30 pF) CPU = 66.6/100 MHz Parameter tP tH tL tR tF tD tJC Period High Time Low Time Output Rise Edge Rate Output Fall Edge Rate Duty Cycle Jitter, Cycle-to-Cycle Description Test Condition/Comments Measured on rising edge at 1.5V Duration of clock cycle above 2.4V Duration of clock cycle below 0.4V Measured from 0.4V to 2.4V Measured from 2.4V to 0.4V Measured on rising and falling edge at 1.5V Measured on rising edge at 1.5V. Maximum difference of cycle time between two adjacent cycles. Measured on rising edge at 1.5V Covers all CPU/PCI outputs. Measured on rising edge at 1.5V. CPU leads PCI output. 1.5 Min. 30 12.0 12.0 1 1 45 4 4 55 250 Typ. Max. Unit ns ns ns V/ns V/ns % ps
tSK tO fST
Output Skew CPU to PCI Clock Skew
500 4 3
ps ns ms
Frequency Stabilization Assumes full supply voltage reached within from Power-up (cold start) 1 ms from power-up. Short cycles exist prior to frequency stabilization. AC Output Impedance Average value during switching transition. Used for determining series termination value. 30
Zo
IOAPIC Clock Output (Lump Capacitance Test Load = 20 pF) CPU = 66.6/100 MHz Parameter f tR tF tD fST Description Frequency, Actual Output Rise Edge Rate Output Fall Edge Rate Duty Cycle Test Condition/Comments Frequency generated by crystal oscillator Measured from 0.4V to 2.0V Measured from 2.0V to 0.4V Measured on rising and falling edge at 1.25V 1 1 45 Min. Typ. 14.31818 4 4 55 1.5 Max. Unit MHz V/ns V/ns % ms
Frequency Stabilization Assumes full supply voltage reached within from Power-up (cold start) 1 ms from power-up. Short cycles exist prior to frequency stabilization. AC Output Impedance Average value during switching transition. Used for determining series termination value. 15
Zo
REF0:1 Clock Output (Lump Capacitance Test Load = 20 pF) CPU = 66.6/100 MHz Parameter f tR tF tD fST Description Frequency, Actual Output Rise Edge Rate Output Fall Edge Rate Duty Cycle Frequency Stabilization from Power-up (cold start) AC Output Impedance Test Condition/Comments Frequency generated by crystal oscillator Measured from 0.4V to 2.4V Measured from 2.4V to 0.4V Measured on rising and falling edge at 1.5V. Assumes full supply voltage reached within 1 ms from power-up. Short cycles exist prior to frequency stabilization. Average value during switching transition. Used for determining series termination value. 40 0.5 0.5 45 Min. Typ. 14.318 2 2 55 3 Max. Unit MHz V/ns V/ns % ms
Zo
12
W149
48-MHz Clock Output (Lump Capacitance Test Load = 20 pF= 66.6/100 MHz CPU = 66.6/100 MHz Parameter f fD m/n tR tF tD fST Description Frequency, Actual PLL Ratio Output Rise Edge Rate Duty Cycle Frequency Stabilization from Power-up (cold start) Test Condition/Comments Determined by PLL divider ratio (see m/n below) (14.31818 MHz x 57/17 = 48.008 MHz) Measured from 0.4V to 2.4V 0.5 0.5 45 Min. Typ. 48.008 +167 57/17 2 2 55 3 V/ns V/ns % ms Max. Unit MHz ppm
Deviation from 48 MHz (48.008 - 48)/48
Output Fall Edge Rate Measured from 2.4V to 0.4V Measured on rising and falling edge at 1.5V 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.
40
24-MHz Clock Output (Lump Capacitance Test Load = 20 pF= 66.6/100 MHz CPU = 66.6/100 MHz Parameter f fD m/n tR tF tD fST Description Frequency, Actual PLL Ratio Output Fall Edge Rate Duty Cycle Frequency Stabilization from Power-up (cold start) AC Output Impedance Test Condition/Comments Determined by PLL divider ratio (see m/n below) (14.31818 MHz x 57/34 = 24.004 MHz) 0.5 0.5 45 Measured from 2.4V to 0.4V Measured on rising and falling edge at 1.5V Assumes full supply voltage reached within 1 ms from power-up. Short cycles exist prior to frequency stabilization. Average value during switching transition. Used for determining series termination value. 40 Min. Typ. 24.004 +167 57/34 2 2 55 3 V/ns V/ns % ms Max. Unit MHz ppm
Deviation from 24 MHz (24.004 - 24)/24 Output Rise Edge Rate Measured from 0.4V to 2.4V
Zo
Ordering Information
Ordering Code W149 Document #: 38-00856-A Package Name H Package Type 48-Pin SSOP (300-mil)
13
W149
Package Diagram
48-Pin Shrink Small Outline Package (SSOP, 300 mils)
Summary of nominal dimensions in inches: Body Width: 0.296 Lead Pitch: 0.025 Body Length: 0.625 Body Height: 0.102
(c) Cypress Semiconductor Corporation, 2000. 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.

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Price & Availability of W149

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