Motherboard Clock Generator with DIMM Support Preliminary PRODUCT
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SC678
Motherboard Clock Generator with DIMM Support
Preliminary PRODUCT FEATURES Designed support Intel chipset Specification clocks SDRAM clocks DIMs. synchronous clocks. Optional common mixed supply mode: (VDD VDDS VDDC =VDDI 3.3V) (VDD VDDS 3.3V, VDDC=VDDI 2.5V) 250ps skew among SDRAM clocks. 250ps skew among clocks. Controlled current output buffers 2-Wire serial interface Programmable registers featuring: enable/disable each output mode tri-state, test, normal IOAPIC clocks multiprocessor support. 56-pin SSOP package BLOCK DIAGRAM
FREQUENCY TABLE
60.0 66.6 30.0 33.3
CONNECTION DIAGRAM
REF1 REF2 XOUT VDDS PCI_F PCI1 PCI2 PCI3 PCI4 PCI5 VDDS PCI6 48M1 48M2 VDDS SDRAM13 SDRAM12 SDRAM11 VDDS SDATA SDCLK VDDI IOAPIC1 IOAPIC2 CPU1 CPU2 VDDC CPU3 CPU4 CPU5 SDRAM1 SDRAM2 VDDS SDRAM3 SDRAM4 SDRAM5 SDRAM6 VDDS SDRAM7 SDRAM8 SDRAM9 SDRAM10
REF(1:2)
XOUT
VDDI VDDS
IOAPIC(1:2)
(1:2)
VDDC
Sdata Sclock
CPU(1:5) SDRAM(1:13) PCI(1:6) PCI_F
Clock Gen.
VDDS VDDS
INTERNATIONAL MICROCIRCUITS, INC. COCHES MILPITAS, 95035. TEL: 408-263-6300. 408-263-6571
Rev.1.2
7/31/97 Page
SC678
Motherboard Clock Generator with DIMM Support
Preliminary DESCRIPTION
Name TYPE OSC1 Description On-chip reference oscillator input pin. Requires either external crystal (nominally 14.318 MHz) external reference signal. internal loading capacitor. chip reference oscillator output pin. Drives external parallel resonant crystal, left unconnected. internal loading capacitor. Frequency select input pins. frequency select table page 1.This internal pull-up Output Enable. when pulled logis (LOW) Tri-states clock outputs. This internal pull-up Clock outputs. frequency select table page
Xout
OSC1
CPU(1:5)
VDDC
PADI4 PAD4 BUF1
PCI_F PCI(1:6)
VDDP VDDS
BUF5 BUF5
Free running copy output clocks. Powered VDDP volts. output clocks. Powered VDDP volts.
SDRAM(1:13)
VDDS
BUF4
SDRAM clock outputs. frequency select table page frequency select table page
48M(1:2) SCLK SDATA IOAPIC(1:2) REF1 REF2
VDDS VDDI
BUF5 BUF2 BUF4 BUF5
fixed clock. volt powered. serial clock 2-wire control interface. internal pull-up resistor. serial data 2-wire control interface. internal pull-up resistor. 14.31818 clock. volt powered. High Drive 14.31818 reference clock. volt powered. 14.31818 reference clock. volt powered. Ground pins device.
VDDI VDDC VDDS
Power supply 3.3V PCI, SDRAM fixed clock buffer. Power supply 2.5V/3.3V IOAPIC clock buffers. Power supply 2.5V/3.3V clock buffers. Power supply pins 3.3V PCI, SDRAM fixed clock buffers.
INTERNATIONAL MICROCIRCUITS, INC. COCHES MILPITAS, 95035. TEL: 408-263-6300. 408-263-6571
Rev.1.2
7/31/97 Page
SC678
Motherboard Clock Generator with DIMM Support
Preliminary 2-WIRE CONTROL INTERFACE
2-wire control interface implements write only slave interface. device cannot read back. Sub-addressing supported, thus preceeding bytes must sent order change control bytes. 2-wire control interface allows each clock output individually enabled disabled. During normal data transfer, SDATA signal only changes when SDCLK signal low, stable when SDCLK high. There exceptions this. high transition SDATA while SDCLK high used indicate start data transfer cycle. high transition SDATA while SDCLK high indicates data transfer cycle. Data always sent complete 8-bit bytes, after which acknowledge generated. first byte transfer cycle 7-bit address with Read/Write LSB. Data transferred first. device will respond writes bytes (max) data address generating acknowledge (low) signal SDATA wire following reception each byte. device will respond other control interface conditions. Previously control registers retained.
SERIAL CONTROL REGISTERS
NOTE: Pin# column lists affected number where applicable. @Pup column gives state true power Bytes values shown only true power Following acknowledge Address Byte (D2), additional bytes must sent: "Command Code byte, "Byte Count" byte. Although data (bits) these bytes considered "don't care", they must sent will acknowledged.
After Command Code Count bytes have been acknowledged, below desrcibed sequence (Byte Byte Byte2, will valid acknowledged.
INTERNATIONAL MICROCIRCUITS, INC. COCHES MILPITAS, 95035. TEL: 408-263-6300. 408-263-6571
Rev.1.2
7/31/97 Page
SC678
Motherboard Clock Generator with DIMM Support
Preliminary SERIAL CONTROL REGISTERS (Cont.)
BYTE Function Select Register enable, Stopped)
@Pup
Pin#
Description
Reserved, Don't Reserved, Don't Reserved, Don't Reserved, Don't Reserved, Don't Reserved, Don't Bit1 Bit0 Tri-State Reserved Test Mode Normal
IMPORTANT NOTE
Reserved bits intended possible future functions. important that they logic times otherwise data sheet specifications cannot guaranteed.
Function Table Function Description Tri-State Test Mode Normal SEL=1 Normal SEL=0 Outputs SDRAM Hi-Z Hi-Z Tclk/2 Tclk 14.318 14.318
Hi-Z Tclk/2
Hi-Z Tclk/4 CPU/2 CPU/2
IOAPIC Hi-Z Tclk 14.318 14.318
Notes: Tclk test clock over driven input during test mode.
BYTE Clock Register enable, Stopped) @Pup Pin# Description Reserved Reserved Reserved CPU5 enable/Stopped CPU4 enable/Stopped CPU3 enable/Stopped CPU2 enable/Stopped CPU1 enable/Stopped
INTERNATIONAL MICROCIRCUITS, INC. COCHES MILPITAS, 95035. TEL: 408-263-6300. 408-263-6571
Rev.1.2
7/31/97 Page
SC678
Motherboard Clock Generator with DIMM Support
Preliminary SERIAL CONTROL REGISTERS (Continued)
BYTE Clock Register enable, Stopped) @Pup Pin# Description Reserved PCI_F enable/Stopped PCI6 enable/Stopped PCI5 enable/Stopped PCI4 enable/Stopped PCI3 enable/Stopped PCI2 enable/Stopped PCI1 enable/Stopped
BYTE SDRAM Clock Register enable, Stopped @Pup Pin# Description SDRAM8 enable/Stopped SDRAM7 enable/Stopped SDRAM6 enable/Stopped SDRAM5 enable/Stopped SDRAM4 enable/Stopped SDRAM3 enable/Stopped SDRAM2 enable/Stopped SDRAM1 enable/Stopped
BYTE Additional SDRAM Clock Register enable, Stopped) @Pup Pin# Description Reserved Reserved Reserved SDRAM13 enable/Stopped SDRAM12 enable/Stopped SDRAM11 enable/Stopped SDRAM10 enable/Stopped SDRAM9 enable/Stopped
INTERNATIONAL MICROCIRCUITS, INC. COCHES MILPITAS, 95035. TEL: 408-263-6300. 408-263-6571
Rev.1.2
7/31/97 Page
SC678
Motherboard Clock Generator with DIMM Support
Preliminary SERIAL CONTROL REGISTERS(Continued)
BYTE Peripheral Control enable, Stopped) @Pup Pin# Description Reserved REF1 enable/Stopped IOAPIC2 enable/Stopped IOAPIC1 enable/Stopped Reserved 48M2 enable/Stopped 48M1 enable/Stopped REF2 enable/Stopped
BYTE Reserved Register @Pup Pin# Description Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved
MAXIMUM RATINGS
This device contains circuitry protect inputs against damage high static voltages electric field; however, precautions should taken avoid application voltage higher than maximum rated voltages this circuit. proper operation, Vout should constrained range: VSS<(Vin Vout)<VDD Unused inputs must always tied appropriate logic voltage level (either VDD).
Voltage Relative VSS: Voltage Relative VDD: Storage Temperature: Operating Temperature: Maximum Power Supply:
-0.3V 0.3V
INTERNATIONAL MICROCIRCUITS, INC. COCHES MILPITAS, 95035. TEL: 408-263-6300. 408-263-6571
Rev.1.2
7/31/97 Page
SC678
Motherboard Clock Generator with DIMM Support
Preliminary
ELECTRICAL CHARACTERISTICS
Characteristic Input Voltage Input High Voltage Input Current Input High Current Tri-State leakage Current Dynamic Supply Current Static Supply Current Short Circuit Current Symbol Isdd Units Conditions
66.6 MHz, 33.3 output time seconds
VDDP=3.465V 3.135V VDDC= VDDI 2.375V 2.9V,
SWITCHING CHARACTERISTICS
Characteristic Output Duty Cycle Offset Buffer Skew Buffer Outputs Period Adjacent Cycles Jitter Spectrum Bandwidth from Center Overshoot/Undershoot Beyond Power Rails Ring Back Exclusion Symbol tOFF tSKEW Vover VRBE Units ohms source inch load note1 Conditions Measured 1.5V Load Measured 1.5V Load Measured 1.5V
VDDP =3.30V VDDC VDDI 2.5V
note Ring Back must enter this range.
INTERNATIONAL MICROCIRCUITS, INC. COCHES MILPITAS, 95035. TEL: 408-263-6300. 408-263-6571
Rev.1.2
7/31/97 Page
SC678
Motherboard Clock Generator with DIMM Support
Preliminary
TYPE BUFFER CHARACTERISTICS CPUCLK(1:5)
Characteristic Pull-Up Current Pull-Up Current Pull-Down Current Pull-Down Current Rise/Fall Time Between Rise/Fall Time Between Symbol IOHmin IOHmax IOLmin IOLmax TRFmin TRFmax Units Conditions Vout Vout Vout Vout Load Load
VDDP =3.30V VDDC= VDDI 2.5V
TYPE BUFFER CHARACTERISTICS IOAPIC(1:2)
Characteristic Pull-Up Current Pull-Up Current Pull-Down Current Pull-Down Current Rise/Fall Time Between Rise/Fall Time Between Symbol IOHmin IOHmax IOLmin IOLmax TRFmin TRFmax Units Conditions Vout Vout Vout Vout Load Load
=VDDF =3.30V VDDC VDDI 2.5V
TYPE BUFFER CHARACTERISTICS REF1 SDRAM(1:13)
Characteristic Pull-Up Current Pull-Up Current Pull-Down Current Pull-Down Current Rise/Fall Time Between Rise/Fall Time Between Symbol IOHmin IOHmax IOLmin IOLmax TRFmin TRFmax Units Conditions Vout 1.65 Vout 3.135 Vout 1.65 Vout Load Load
VDDP =3.30V VDDC= VDDI 2.5V
INTERNATIONAL MICROCIRCUITS, INC. COCHES MILPITAS, 95035. TEL: 408-263-6300. 408-263-6571
Rev.1.2
7/31/97 Page
SC678
Motherboard Clock Generator with DIMM Support
Preliminary
TYPE BUFFER CHARACTERISTICS REF2 PCI(1:6,F)
Characteristic Pull-Up Current Pull-Up Current Pull-Down Current Pull-Down Current Rise/Fall Time Between Rise/Fall Time Between Symbol IOHmin IOHmax IOLmin IOLmax TRFmin TRFmax Units Conditions Vout Vout 3.135 Vout 1.95 Vout Load Load
VDDP =3.30V VDDC= VDDI 2.5V
CRYSTAL REFERENCE OSCILLATOR PARAMETERS
Characteristic Frequency Tolerence Symbol Mode Capacitance Bias Voltage Startup time Load Capacitance Effective Series resonant resistance Power Dissipation Shunt Capacitance VBIAS 0.3Vdd 12.00 14.31818 Vdd/2 0.7Vdd 16.00 +/-100 Ohms crystals rated load. note Units Calibration note Stability +60C) note Aging (first year 25C) note Parallell Resonant Capacitance Xout pins ground (each) Conditions
0.10
note
crystals internal package capacitance (total) maximum accuracy,the total circuit loading capacitance should equal This loading capacitance effective capacitance across crystal pins includes device capacitance (CP) parallel with circuit traces, clock generator onboard discrete load capacitors. Budgeting Calculations Typical trace capacitance, half inch) Load crystal therefore Clock generator internal capacitance Load crystal therefore 18.0 total parasitic capacitance would therefore 20.0.0 Note recommended manditory that crystal meets these specifications.
INTERNATIONAL MICROCIRCUITS, INC. COCHES MILPITAS, 95035. TEL: 408-263-6300. 408-263-6571
Rev.1.2
7/31/97 Page
SC678
Motherboard Clock Generator with DIMM Support
Preliminary PACKAGE DRAWING DIMENSIONS SSOP OUTLINE DIMENSIONS
SYMBOL
INCHES 0.095 0.008 0.088 0.008 0.005 0.292 0.400 0.10 0.024 0.085 0.102 0.012 0.090 0.010 0.296 0.025 0.406 0.013 0.032 0.093 0.410 0.016 0.040 0.100 0.110 0.016 0.092 0.0135 0.010 0.299 2.41 0.20 2.24
MILLIMETERS 2.59 0.31 2.29 0.254 7.52 0.635 10.16 0.25 0.61 2.16 10.31 0.33 0.81 2.36 10.41 0.41 1.02 2.54 2.79 0.41 2.34 0.343 0.254 7.59
0.203 0.127 7.42
ORDERING INFORMATION
Part Number IMISC678AYB Note:
Marking:
Package Type SSOP
Production Flow Commercial,
ordering part number formed combination device number, device revision, package style, screening shown below.
Example: SC678AYB Date Code,
IMISC678AYB Flow Commercial, Package SSOP Revision Device Number Purchase components International Microcircuits, Inc. sublicensed Associated Companies conveys license under Philips Patent Rights these components system, provided that system conforms Standard Specification defined Philips.
INTERNATIONAL MICROCIRCUITS, INC. COCHES MILPITAS, 95035. TEL: 408-263-6300. 408-263-6571
Rev.1.2
7/31/97 Page
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