Pentium® III Processor for the PGA370 Socket at 500 MHz to 866 MHz
3.2
AGTL+ Signal Quality Specifications and Measurement
Guidelines
Many scenarios have been simulated to generate a set of AGTL+ layout guidelines which are
available in the appropriate platform design guide. Refer to the Intel® Pentium® II Processor
Developer's Manual (Order Number 243502) for the AGTL+ buffer specification.
Table 18 provides the AGTL+ signal quality specifications for the processor for use in simulating
signal quality at the processor pins.
The Pentium III processor for the PGA370 socket maximum allowable overshoot and undershoot
specifications for a given duration of time are detailed in Table 20 through Table 22. Figure 15
shows the AGTL+ ringback tolerance and Figure 16 shows the overshoot/undershoot waveform.
Table 18. AGTL+ Signal Groups Ringback Tolerance Specifications at the Processor
Pins 1, 2, 3
T# Parameter
Min
Unit
Figure
Notes
α: Overshoot
100
0.50
±200
200
mV
ns
15
15
15
15
15
4, 8
τ: Minimum Time at High
ρ: Amplitude of Ringback
φ: Final Settling Voltage
mV
mV
ns
5, 6, 7, 8
8
δ: Duration of Squarewave Ringback
N/A
NOTES:
1. Unless otherwise noted, all specifications in this table apply to all Pentium III processors frequencies.
2. Specifications are for the edge rate of 0.3 - 0.8V/ns. See Figure 15 for the generic waveform.
3. All values specified by design characterization.
4. Please see Table 20 for maximum allowable overshoot.
5. Ringback between V
+ 100 mV and V
+ 200 mV or V
- 200 mV and V
- 100 mVs requires the
REF
REF
REF
REF
®
®
flight time measurements to be adjusted as described in the Intel AGTL+ Specifications (Intel Pentium II
Developers Manual). Ringback below V + 100 mV or above V - 100 mV is not supported.
REF
REF
6. Intel recommends simulations not exceed a ringback value of V
sources of system noise.
±200 mV to allow margin for other
REF
7. A negative value for ρ indicates that the amplitude of ringback is above V
. (i.e., φ = -100 mV specifies the
REF
signal cannot ringback below V
+ 100 mV).
REF
8. φ and ρ: are measured relative to V . α: is measured relative to V
+ 200 mV.
REF
REF
Figure 15. Low to High AGTL+ Receiver Ringback Tolerance
τ
α
VREF + 0.2
φ
V REF
ρ
V REF - 0.2
δ
0.7V Clk Ref
V start
Clock
Time
Note: High to low case is analogous
Datasheet
35
INTEL [ INTEL ]
