Intel III 866 MHz 80526PZ866256 User Manual
Product codes
80526PZ866256
Datasheet
51
Pentium
®
III Processor for the PGA370 Socket at 500 MHz to 1.13 GHz
3.3.6
Determining if a System Meets the Overshoot/Undershoot
Specifications
Specifications
The overshoot/undershoot specifications listed in the following tables 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 (duration,
AF and magnitude). While each overshoot on its own may meet the overshoot specification, when
you add the total impact of all overshoot events, the system may fail. A guideline to ensure a
system passes the overshoot and undershoot specifications is shown below. It is important to meet
these guidelines; otherwise, contact your Intel field representative.
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 (duration,
AF and magnitude). While each overshoot on its own may meet the overshoot specification, when
you add the total impact of all overshoot events, the system may fail. A guideline to ensure a
system passes the overshoot and undershoot specifications is shown below. It is important to meet
these guidelines; otherwise, contact your Intel field representative.
1. Insure no signal (CMOS or AGTL+/AGTL) ever exceed 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
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. 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.
these worst case overshoot or undershoot events meet the specifications (measured time <
specifications) in the table (where AF=1), then the system passes.
The following notes apply to
Table 25
through
Table 27
.
NOTES:
1. Overshoot/Undershoot Magnitude = 2.18 V is an Absolute value and should never be exceeded
2. Overshoot is measured relative to V
2. Overshoot is measured relative to V
SS
.
3. Undershoot is measured relative to V
TT
4. Overshoot/Undershoot Pulse Duration is measured relative to 1.635 V.
5. Ringbacks below V
5. Ringbacks below V
TT
can not be subtracted from Overshoots/Undershoots
6. Leser Undershoot does not allocate longer or larger Overshoot
7. OEM's are encouraged to follow Intel provided layout guidelines. Consult the layout guidelines
7. OEM's are encouraged to follow Intel provided layout guidelines. Consult the layout guidelines
provided in the specific platform design guide.
8. All values specified by design characterization
NOTES:
1. BCLK period is 10 ns.
2. Measurements taken at the processor socket pins on the solder-side of the motherboard.
2. Measurements taken at the processor socket pins on the solder-side of the motherboard.
Table 25. 100 MHz AGTL+ / AGTL Signal Group Overshoot/Undershoot Tolerance at
Processor Pins
1,2
Overshoot/
Undershoot
Magnitude
Maximum Pulse Duration at Tj = 80 °C
(ns)
Maximum Pulse Duration at Tj = 85 °C
(ns)
AF = 0.01
AF = 0.1
AF = 1
AF = 0.01
AF = 0.1
AF = 1
2.18 V
20
2.53
0.25
18.6
1.86
0.18
2.13 V
20
4.93
0.49
20
3.2
0.32
2.08 V
20
9.1
0.91
20
6.1
0.6
2.03 V
20
16.6
1.67
20
11.4
1.1
1.98 V
20
20
3.0
20
20
2
1.93 V
20
20
5.5
20
20
6.6
1.88 V
20
20
10
20
20
20