26 Datasheet
Electrical Specifications
3. If multiple overshoots and/or multiple undershoots occur, measure the worst-case pulse duration for each magnitude and compare the results against the AF = 1 specifications. If all of these worst-case overshoot or undershoot events meet the specifications (measured time < specifications) in the table (where AF = 1), then the system passes.
NOTES: The following notes apply to Tabl e 2-14 through Table2-21:
1. Absolute Maximum Overshoot magnitude of 1.8V must never be exceeded.
2. Absolute Maximum Overshoot is measured referenced to GND. Pulse duration of overshoot is measured
relative to VCTERM.
3. Absolute Maximum Undershoot and Pulse Duration of undershoot is measured relative to VCTERM.
4. Ringback below VCTERM cannot be subtracted from overshoots/undershoots.
5. Lesser undershoot does not allocate overshoot with longer duration or greater magnitude.
6. All values specified by design characterization.
Table 2-13. Source Synchronous AGTL+ Signal Group and Wired-OR Signal Group Absolute Overshoot/Undershoot Tolerance
Parameter Description Specification Units
VCTERM I/O power supply voltage (nominal). 1.20 V
VMAX Maximum absolute voltage for system bus signals at the input
of the receiver buffers. 1.80 V
VMIN Minimum absolute voltage for system bus signals at the input of
the receiver buffers. –0.60 V
Overshoot Time dependent overshoot amount above VCTERM . 1
NOTES:
1. These parameters cannot be specified in absolute terms.
Undershoot Time dependent undershoot amount below GND. 1
Table 2-14. Itanium® 2 Processors (900 MHz, 1.0 GHz, 1.3G Hz , 1 .4GHz, 1.5GH z/ 6MB) Source Synchronous AGTL+ Signal Group Time Dependent Overshoot/Undershoot Tolerance for 400 MHz System Bus
Absolute
Maximum (V) Pulse Duration (ns)
Over-
shoot Under-
shoot AF = 11
NOTES:
1. Activity factor = 1 means signal toggles every 5ns.
AF = 0.75 AF = 0.5 AF = 0.25 AF = 0.1 AF = 0.05 AF = 0.01
1.8 –0.6 0.0083 0.0089 0.0137 0.02750 0.0688 0.1376 0.6863
1.75 –0.55 0.0206 0.0276 0.0413 0.0827 0.2067 0.4139 2.0680
1.7 –0.5 0.0621 0.0828 0.1239 0.2480 0.6207 1.2420 2.5
1.65 –0.45 0.1851 0.2470 0.3702 0.7392 1.8500 2.5 2.5
1.6 –0.4 0.5477 0.7296 1.0972 2.1915 2.5 2.5 2.5
1.55 –0.35 1.6100 2.1451 2. 5 2.5 2.5 2.5 2.5
1.5 –0.3 2.5 2.5 2.5 2.5 2.5 2.5 2.5
1.45 –0.25 2.5 2.5 2.5 2.5 2.5 2.5 2.5