C lock Jitter Specs - Low Power D ifferential Outputs
PARA M E TER SYMBOL CONDITIONS M IN M A X UNITS NOTE S
CP U J itter - Cyc le to Cycle CP UJ C2C Differential M eas urem ent 85 ps 1
SRC J itter - Cyc le to Cycle SRCJ C2C Differential M eas urem ent 125 ps 1,2
DOT J itter - Cyc le to Cycle DOTJ C2C Differential M eas urem ent 250 ps 1
1
JItter spec s are spec ified as m easured on a cloc k c har acterization board. Sy stem designers need to tak e s pecial c are not to us e these numbers , as the in-sy s tem performance will be
som ewhat degraded. T he rec eiver EMT S (c hispet or CPU ) w ill hav e the rec eiver jitter s pec s as m easured ina real s ystem.
2
Phas e jitter requirement: The deisgnated G e2 outputs w ill m eet the reference c loc k jitter requiremernts from the PC I Ex pres s G en2 Bas e Spec . The tes t is perform ed on a com ponnet
tes t board under quiet c ondittions w ith all outputs on. J itter analys is is performed us ing the standardized tool prov ided by the PCI SIG .
NO TES o n DIF O u tput Jitter: ( un less oth erw ise n ot ed, g uaranteed b y d esig n and characteriz ation , no t 100% tested in prod uct io n).
AC Electrical Characteristics - Low Power Differential Outputs
PARAMETER SYMBOL CONDITIONS MIN MAX UNITS NOTES
Rising Edge Slew Rate tSLR Averaging on 2.5 4 V/ns 2, 3
Falling Edge Slew Rate tFLR Averaging on 2.5 4 V/ns 2, 3
Slew Rate Variation tSLVAR Averaging on 20 % 1, 10
Differential Voltage Swing VSWING Averaging off 300 mV 2
Crossing Point Voltage VXABS Averaging off 300 550 mV 1,4,5
Crossing Point Variation VXABSVAR Averaging off 140 mV 1,4,9
Maximum Output Voltage VHIGH Averaging off 1150 mV 1,7
Minimum Output Voltage VLOW Averaging off -300 mV 1,8
Duty Cycle DCYC Averaging on 45 55 % 2
CPU Skew CPUSKEW Averaging on 100 ps
CPU[1:0] Skew CPUSKEW10 Differential Measurement 100 ps 1
CPU[2_ITP:0] Skew CPUSKEW20 Differential Measurement 150 ps 1
SRC[10:0] Skew SRCSKEW Differential Measurement 3000 ps 1,6,11
1
Measurement taken for single ended waveform on a component test board (not in system)
2
Measurement taken from differential waveform on a component test board. (not in system)
3
Slew rate emastured through V_swing voltage range centered about differential zero
4
Vcross is defined at the voltage where Clock = Clock#, measured on a component test board (not in system)
5
Only applies to the differential rising edge (Clock rising, Clock# falling)
NOTES on DIF Output AC Specs: (unless otherwise noted, guaranteed by design and characterization, not 100% tested in production).
9
The total variation of all Vcross measurements in any particular system. Note this is a subset of V_cross min/mas (V_Cross absolute) allowed. The intent is to limit Vcross induced
modulation by setting C_cross_delta to be smaller than V_Cross absolute.
10
Matching applies to rising edge rate for Clock and falling edge rate for Clock#. It is measured using a +/-75mV window centered on the average cross point where Clock rising meets
Clock# falling. The median cross point is used to calculate the voltage thresholds the oscilloscope is to use for the edge rate calculations.
6
Total distributed intentional SRC to SRC skew. PCIE Gen2 outputs (SRC3, 4, 6 and 7) will have 0 nominal skew. Maximum allowable interpair skew is 150 ps.
7
The max voltage including overshoot.
8
The min voltage including undershoot.
11
For PCIe Gen2 compliant devices, SRC 3, 4, 6, and 7 will have 0 ps nominal skew.
NOTES on DC Parameters: (unless otherwise noted, guaranteed by design and characterization, not 100% tested in production).
1
Signal is required to be monotonic in this region.
2
input leakage current does not include inputs with pull-up or pull-down resistors
3
3.3V referenced inputs are: PCI_STOP#, CPU_STOP#, TME, SRC5_EN, ITP_EN, SCLKL, SDATA, TESTMODE, TESTSEL, CKPWRGD and CR# inputs if selected.
4
Intentionally blank
5
Maximum VIH is not to exceed VDD
6
Human Body Model
7
Operation under these conditions is neither implied, nor guaranteed.
8
Frequency Select pins which have tri-level input
9
PCI3/CFG0 is optional
10
If present. Not all parts have this feature.
