W164 Spread Spectrum Desktop/Notebook System Frequency Generator Features Key Specifications • Maximized EMI suppression using Cypress’s Spread Spectrum technology • Reduces measured EMI by as much as 10 dB • I2C programmable to 153 MHz (16 selectable frequencies) • Two skew-controlled copies of CPU output • SEL100/66# selects CPU frequency (100 or 66.8 MHz) • Seven copies of PCI output (synchronous w/CPU output) • One copy of 14.31818-MHz IOAPIC output • One copy of 48-MHz USB output • Selectable 24-/48-MHz output is determined by resistor straps on power-up • One high-drive output buffer that produces a copy of the 14.318-MHz reference • Isolated core VDD pin for noise reduction Supply Voltages:....................................... VDDQ3 = 3.3V±5% VDDQ2 = 2.5V±5% CPU Cycle to Cycle Jitter: ........................................... 200 ps CPU, PCI Output Edge Rate: ......................................... ≥1 V/ns CPU0:1 Output Skew: ................................................ 175 ps PCI_F, PCI1:6 Output Skew: .......................................500 ps CPU to PCI Skew: .............................. 1 to 4 ns (CPU Leads) REF2X/SEL48#, SCLOCK, SDATA ................ 250-kΩ pull-up Note: Internal pull-up resistors should not be relied upon for setting I/O pins HIGH. Table 1. Pin Selectable Frequency SEL100/66# Block Diagram PCI 1 100 MHz 33.3 MHz 0 66.8 MHz 33.4 MHz Pin Configuration VDDQ3 REF2X/SEL48# GND X1 X2 CPU(0:1) XTAL OSC VDDQ3 IOAPIC PLL Ref Freq VDDQ2 CPU0 X1 X2 GND PCI_F PCI1 PCI2 PCI3 PCI4 VDDQ3 PCI5 PCI6 VDDQ3 48MHz 24/48MHz 28 27 26 25 24 23 22 21 20 19 18 17 16 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 GND REF2X/SEL48# VDDQ3 VDDQ2 IOAPIC VDDQ2 CPU0 CPU1 VDDQ3 GND SDATA SCLOCK SEL100/66# GND CPU1 GND 100/66#_SEL PLL 1 ÷2/÷3/÷4 VDDQ3 PCI_F PCI1 PCI2 PCI3 PCI4 SDATA SCLOCK PCI5 2 I C LOGIC PCI6 GND VDDQ3 48MHz PLL2 24/48MHz GND Cypress Semiconductor Corporation • 3901 North First Street • San Jose • CA 95134 • 408-943-2600 December 16, 1999, rev. ** W164 Pin Definitions Pin No. Pin Type CPU0:1 22, 21 O CPU Clock Outputs 0 through 1: These two CPU clocks run at a frequency set by SEL100/66#. Output voltage swing is set by the voltage applied to VDDQ2. PCI1:6 PCI_F 5, 6, 7, 8, 10, 11, 4 O PCI Clock Outputs 1 through 6 and PCI_F: These seven PCI clock outputs run synchronously to the CPU clock. Voltage swing is set by the power connection to VDDQ3. IOAPIC 24 O I/O APIC Clock Output: Provides 14.318-MHz fixed frequency. The output voltage swing is set by the power connection to VDDQ2. 48MHz 13 O 48-MHz Output: Fixed 48-MHz USB clock. Output voltage swing is controlled by voltage applied to VDDQ3. 24/48MHz 14 O 24-MHz or 48-MHz Output: Frequency is set by the state of pin 27 on power-up. REF2X/SEL48# 27 I/O I/O Dual-Function REF2X and SEL48# pin: Upon power-up, the state of SEL48# is latched. The initial state is set by either a 10K resistor to GND or to VDD. A 10K resistor to GND causes pin 14 to output 48 MHz. If the pin is strapped to V DD, pin 14 will output 24 MHz. After 2 ms, the pin becomes a high-drive output that produces a copy of 14.318 MHz. SEL100/66# 16 I Frequency Selection Input: Selects CPU clock frequency as shown in Table 1 on page 1. SDATA 18 I/O I2C Data Pin: Data should be presented to this input as described in the I2C section of this data sheet. Internal 250-kΩ pull-up resistor. SCLOCK 17 I I2C Clock Pin: The I2C data clock should be presented to this input as described in the I2C section of this data sheet. X1 1 I Crystal Connection or External Reference Frequency Input: Connect to either a 14.318-MHz crystal or other reference signal. X2 2 I Crystal Connection: An input connection for an external 14.318-MHz crystal. If using an external reference, this pin must be left unconnected. VDDQ3 9, 12, 20, 26 P Power Connection: Power supply for core logic and PLL circuitry, PCI, 48-/24-MHz, and Reference output buffers. Connect to 3.3V supply. VDDQ2 23, 25 P Power Connection: Power supply for IOAPIC and CPU output buffers. Connect to 2.5V supply. 3, 15, 19, 28 G Ground Connections: Connect all ground pins to the common system ground plane. Pin Name GND Pin Description l/O pin is then latched. Next the output buffer is enabled which converts the l/O pin into an operating clock output. The 2-ms timer is started when VDD reaches 2.0V. The input bit can only be reset by turning VDD off and then back on again. Functional Description I/O Pin Operation Pin 27 is a dual-purpose l/O pin. Upon power-up this pin acts as a logic input, allowing the determination of assigned device functions. A short time after power-up, the logic state of the pin is latched and the pin becomes a clock output. This feature reduces device pin count by combining clock outputs with input select pins. It should be noted that the strapping resistor has no significant effect on clock output signal integrity. The drive impedance of clock output is 25Ω (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. An external 10-kΩ “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. When the clock output is enabled following the 2-ms input period, a 14.318-MHz 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. Upon W164 power-up, the first 2 ms of operation is used for input logic selection. During this period, the Reference clock output buffer is three-stated, allowing the output strapping resistor on the 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 the 2 W164 VDD Output Strapping Resistor Series Termination Resistor 10 kΩ (Load Option 1) Clock Load W164 Power-on Reset Timer Output Buffer Hold Output Low Output Three-state Q 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 W164 Power-on Reset Timer R Output Buffer Q Resistor Value R Hold Output Low Output Three-state Clock Load D Data Latch Figure 2. Input Logic Selection Through Jumper Option chipset. Clock device register changes are normally made upon system initialization, if 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 W164 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 W164 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 Operation Data is written to the W164 in ten bytes of eight bits each. Bytes are written in the order shown in Table 3. 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 PCI slots. CPU Clock Frequency Selection Provides CPU/PCI frequency selections beyond the 100- and 66.6-MHz selections that are provided by the SEL100/66# pin. Frequency is changed in a smooth and controlled fashion. For alternate microprocessors 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 to X1 input, inter- Production PCB testing. nal PLL is bypassed. Refer to Table 4. (Reserved) Reserved function for future device revision or pro- No user application. Register bit must be writduction device testing. ten as 0. 3 W164 Table 3. Byte Writing Sequence Byte Sequence Byte Name 1 Slave Address 11010010 Commands the W164 to accept the bits in Data Bytes 3–6 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 W164 is 11010010. Register setting will not be made if the Slave Address is not correct (or is for an alternate slave receiver). 2 Command Code Don’t Care Unused by the W164, 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 W164, 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 Don’t Care Refer to Cypress SDRAM drivers. 5 Data Byte 1 6 Data Byte 2 7 Data Byte 3 Refer to Table 4 8 Data Byte 4 9 Data Byte 5 The data bits in these bytes set internal W164 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. 10 Data Byte 6 Bit Sequence Byte Description 4 W164 Writing Data Bytes Table 5 details additional frequency selections that are available through the serial data interface. Each bit in the data bytes controls 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 4 gives the bit formats for registers located in Data Bytes 3–6. Table 6 details the select functions for Byte 3, bits 1 and 0. Table 4. Data Bytes 3–6 Serial Configuration Map Affected Pin Bit(s) Pin No. Data Byte 3 7 -- Pin Name Bit Control Control Function 0 1 -- -- SEL_3 6 -- -- SEL_2 Refer to Table 5 0 5 -- -- SEL_1 Refer to Table 5 0 4 -- -- SEL_0 3 -- -- Frequency Table Selection 2 -- -- (Reserved) 1–0 -- -- 7 -- -- 6 14 24/48MHz 5 -- -- (Reserved) 4 -- -- (Reserved) 3 2 -21 -CPU1 Bit 1 0 0 1 1 -- Default Refer to Table 5 Bit 0 0 1 0 1 0 0 Frequency Controlled by external SEL100/ 66# pin Table 1 Frequency Controlled by BYT3 SEL_(3:0) Table 5 0 -- -- 0 00 Function (See Table 6 for function details) Normal Operation Test Mode Spread Spectrum on All Outputs Three-stated Data Byte 4 (Reserved) Clock output Disable (Reserved) Clock Output Disable (Reserved) -- -- 0 Low Active 1 -- -- 0 -- -- 0 -Low -Active 0 1 -- -- 0 Low Active 1 1 -- -- 0 22 CPU0 7 4 PCI_F Clock Output Disable Low Active 1 6 5 11 10 PCI6 PCI5 Clock Output Disable Clock Output Disable Low Low Active Active 1 1 Clock Output Disable Data Byte 5 4 - -- -- -- 0 3 8 PCI4 Clock Output Disable Low Active 1 2 7 PCI3 Clock Output Disable Low Active 1 1 6 PCI2 Clock Output Disable Low Active 1 5 PCI1 Clock Output Disable Low Active 1 7 -- -- (Reserved) -- -- 0 6 -- -- (Reserved) -- -- 0 5 24 IOAPIC Low Active 1 4 -- -- (Reserved) -- -- 0 3 2 --- --- (Reserved) (Reserved) --- --- 0 0 1 27 REF2X Clock Output Disable Low Active 1[1] 0 27 REF2X Clock Output Disable Low Active 1[1] 0 Data Byte 6 (Reserved) Clock Output Disable Note: 1. Both Bits 0 and 1 of Byte 6 in Table 4 must be programmed as the same value. 5 W164 Table 5. Additional Frequency Selections through Serial Data Interface Data Bytes Input Conditions Output Frequency If Spread Is On Data Byte 3, Bit 3 = 1 Bit 7 SEL_3 Bit 6 SEL_2 Bit 5 SEL_1 Bit 4 SEL_0 CPU, SDRAM Clocks (MHz) PCI Clocks (MHz) Spread Percentage 0 0 0 0 68.5 34.25 ±0.5% Center 0 0 0 1 75 37.5 ±0.5% Center 0 0 1 0 83.3 41.6 ±0.5% Center 0 0 1 1 66.8 33.4 ±0.5% Center 0 1 0 0 103 34.25 ±0.5% Center 0 1 0 1 112 37.3 ±0.5% Center 0 1 1 0 133.3 33.3 ±0.5% Center 0 1 1 1 100 33.3 ±0.5% Center 1 0 0 0 117 39.0 ±0.5% Center 1 0 0 1 117 29.25 ±0.5% Center 1 0 1 0 124 31.0 ±0.5% Center 1 0 1 1 129 32.25 ±0.5% Center 1 1 0 0 138 34.5 ±0.5% Center 1 1 0 1 143 35.75 ±0.5% Center 1 1 1 0 148 37.0 ±0.5% Center 1 1 1 1 153 38.25 ±0.5% Center Table 6. Select Function for Data Byte 3, Bits 0:1 Input Conditions Output Conditions Data Byte 3 Bit 1 Bit 0 CPU0:1 PCI_F, PCI1:6 REF2X, IOAPIC 48MHZ 24MHZ Normal Operation 0 0 Note 2 Note 2 14.318 MHz 48 MHz 24 MHz Test Mode 0 1 X1/2 CPU/2, 3, or 4 X1 X1/2 X1/4 Spread Spectrum 1 0 ±0.5% ±0.5% 14.318 MHz 48 MHz 24 MHz Three-state 1 1 Hi-Z Hi-Z Hi-Z Hi-Z Hi-Z Function Note: 2. CPU and PCI frequency selections are listed in Table 1 and Table 5. 6 W164 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 Supply Current IDDQ3 Combined 3.3V Supply Current CPU0:1 =100 MHz Outputs Loaded[3] 85 mA IDDQ3 Combined 2.5V Supply Current CPU0:1 =100 MHz Outputs Loaded[3] 30 mA Logic Inputs 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 IIH Input High Current[4] 10 µA IIL Input Low Current (SEL100/66#) –5 µA IIH Input High Current (SEL100/66#) 5 µA 50 mV Clock Outputs VOL Output Low Voltage IOL = 1 mA VOH Output High Voltage IOH = –1 mA 3.1 V VOH Output High Voltage IOH = –1 mA 2.2 V IOL Output Low Current IOH Output High Current CPU0:1/IOAPIC CPU0:1 VOL = 1.25V 50 70 100 mA PCI_F, PCI1:6 VOL = 1.5V 60 80 120 mA IOAPIC VOL = 1.25V 40 85 140 mA REF2X VOL = 1.5V 100 130 152 mA 48MHz, 24MHz VOL = 1.5V 40 50 76 mA CPU0:1 VOH = 1.25V 50 70 100 mA PCI_F, PCI1:6 VOH = 1.5V 60 70 120 mA IOAPIC VOH = 1.25V 40 87 155 mA REF2X VOH = 1.5V 100 130 150 mA 48MHz, 24MHz VOH = 1.5V 40 50 94 mA Notes: 3. All clock outputs loaded with maximum lump capacitance test load specified in the AC Electrical Characteristics section. 4. W164 logic inputs have internal pull-up resistors, except SEL100/66# (pull-ups not full CMOS level). 7 W164 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, as seen by External Crystal[6] CIN,X1 X1 Input Capacitance[7] VDDQ3 = 3.3V 1.65 V 13 pF 26 pF Pin X2 unconnected Pin Capacitance/Inductance CIN Input Pin Capacitance COUT Output Pin Capacitance LIN Input Pin Inductance Except X1 and X2 pF pF 7 nH AC Electrical Characteristics TA = 0°C to +70°C, VDDQ3 = 3.3V±5%,VDDQ2 = 2.5V± 5%, 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, CPU0:1 (Lump Capacitance Test Load = 20 pF) CPU = 66.8 MHz Parameter Description Test Condition/Comments CPU = 100 MHz Min. Typ. Max. Min. 15.5 Typ. Max. Unit tP Period Measured on rising edge at 1.25V 15 tH High Time Duration of clock cycle above 2.0V 5.2 3.0 ns tL Low Time Duration of clock cycle below 0.4V 5.0 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. 200 250 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. 20 10 10.5 20 ns Ω Notes: 5. X1 input threshold voltage (typical) is VDD/2. 6. The W164 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. 7. X1 input capacitance is applicable when driving X1 with an external clock source (X2 is left unconnected). 8 W164 PCI Clock Outputs, PCI1:6 and PCI_F (Lump Capacitance Test Load = 30 pF CPU = 66.8/100 MHz Parameter Description Test Condition/Comments 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 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 % tJC Jitter, Cycle-to-Cycle Measured on rising edge at 1.5V. Maximum difference of cycle time between two adjacent cycles. 250 ps tSK Output Skew Measured on rising edge at 1.5V 500 ps tO CPU to PCI Clock Skew Covers all CPU/PCI outputs. Measured on rising edge at 1.5V. CPU 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 Ω 20 IOAPIC Clock Output (Lump Capacitance Test Load = 20 pF) CPU = 66.8/100 MHz Parameter Description Test Condition/Comments Min. Typ. Max. 14.31818 Unit f Frequency, Actual Frequency generated by crystal oscillator MHz tR Output Rise Edge Rate Measured from 0.4V to 2.0V 1 4 V/ns tF Output Fall Edge Rate Measured from 2.0V to 0.4V 1 4 V/ns tD Duty Cycle Measured on rising and falling edge at 1.25V 45 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. 55 % 1.5 ms Ω 15 REF2X Clock Output (Lump Capacitance Test Load = 20 pF) CPU = 66.8/100 MHz Parameter Description Test Condition/Comments Min. Typ. Max. Frequency, Actual Frequency generated by crystal oscillator 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. 9 14.318 Unit f 15 MHz Ω W164 48-MHz and 24-MHz Clock Output (Lump Capacitance Test Load = 20 pF) CPU = 66.8/100 MHz 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. Ordering Information Ordering Code W164 Package Name G Package Type 28-pin SOIC (300 mils) Document #: 38-00841 10 48.008 24.004 MHz +167 ppm 57/17, 57/34 25 Ω W164 Package Diagram 28-Pin Small Outline Integrated Circuit (SOIC, 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.