Intel III 450 MHz 80525PY450512 Data Sheet
Product codes
80525PY450512
44
Datasheet
Signal Quality Specifications
3.2.5
Determining If a System Meets the Overshoot/Undershoot
Specifications
Specifications
The overshoot/undershoot specifications (
through
) specify the allowable
overshoot/undershoot for a single overshoot/undershoot event. However, most systems will have
multiple overshoot and/or undershoot events that each have their own set of parameters
(magnitude, duration, and AF). While each overshoot on its own may meet the overshoot
specification, when you add the total impact of all overshoot events, the system may exceed the
specifications. A guideline to ensure a system passes the overshoot and undershoot specifications is
shown below.
multiple overshoot and/or undershoot events that each have their own set of parameters
(magnitude, duration, and AF). While each overshoot on its own may meet the overshoot
specification, when you add the total impact of all overshoot events, the system may exceed the
specifications. A guideline to ensure a system passes the overshoot and undershoot specifications is
shown below.
1. Ensure no signal (AGTL+ or 1.5 V non-AGTL+) ever exceeds the 1.635 V
OR
2. If only one overshoot/undershoot event magnitude occurs, ensure it meets the over/undershoot
specifications in the following tables. This means that whenever the over/undershoot event
occurs, it always over/undershoots to the same level.
occurs, it always over/undershoots to the same level.
OR
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
(note: multiple overshoot/undershoot events within one clock cycle must have their pulse
durations summed together to determine the total pulse duration). 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.
(note: multiple overshoot/undershoot events within one clock cycle must have their pulse
durations summed together to determine the total pulse duration). 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:
1. BCLK period is 10 ns.
2. These values are specified at the processor core pins.
3. Overshoot/Undershoot Magnitude = 2.3 V is an absolute value and should never be exceeded.
4. Overshoot is measured relative to V
2. These values are specified at the processor core pins.
3. Overshoot/Undershoot Magnitude = 2.3 V is an absolute value and should never be exceeded.
4. Overshoot is measured relative to V
SS
, while undershoot is measured relative to V
TT
.
5. Overshoot/Undershoot Pulse Duration is measured relative to 1.635 V.
Table 20. 100 MHz AGTL+ Signal Group Overshoot/Undershoot Tolerance
Overshoot/Undershoot
Magnitude
Maximum Pulse Duration
Unit
Figure
Notes
1, 2, 3, 4, 5
AF = 0.01
AF = 0.1
AF = 1
2.3 V
20
2.53
0.25
ns
2.25 V
20
4.93
0.49
ns
2.2 V
20
9.1
0.91
ns
2.15 V
20
16.6
1.67
ns
2.1 V
20
20
3.0
ns
2.05 V
20
20
5.5
ns
2.0 V
20
20
10
ns