Eagle Stream Platform

Data Sheet

ID Date Version Classification
814095 04/04/2025 001 Public
Document Table of Contents

Overshoot/Undershoot Tolerance

Overshoot (or undershoot) is the absolute value of the maximum voltage above or below VSS, see Figure: Maximum Acceptable Overshoot/Undershoot Waveform. The overshoot/undershoot specifications limit transitions beyond VCCD or VSS due to the fast signal edge rates. The processor can be damaged by single and/or repeated overshoot or undershoot events on any input, output, or I/O buffer if the charge is large enough (that is, if the over/undershoot is great enough). Baseboard designs which meet signal integrity and timing requirements and which do not exceed the maximum overshoot or undershoot limits listed in the following table will insure reliable IO performance for the lifetime of the processor.

Processor I/O Overshoot/Undershoot Specifications

Signal Group Maximum Undershoot Maximum Overshoot Overshoot Duration Undershoot Duration Notes
DDR5 -0.22×VCCD 1.22×VCCD 0.25×TCH 0.1×TCH 1,2,3,5
Processor Asynchronous Sideband Signals, SVID, miscellaneous and JTAG/Tap Signals -0.35×VCCINFAON 1.35×VCCINFAON 1.25 ns 0.5 ns 1,2,5
System Reference Clock (BCLK(0/1/2/3)) -0.15V 1.15V N/A N/A 1,2,5

PWRGOOD Signal

-0.42V VCCINFAON + 0.28 V 5 ns 5 ns 1,2,4
PMSYNC[6:0] Signals -0.35×VCCINFAON 1.35×VCCINFAON 5 ns 5 ns 1,2
PECI Signal -0.35V 1.35V 5 ns 5 ns 1,2
SVIDDATA Signal -0.3V 1.3V 10 ns 10 ns 1,2

Notes:

  1. These specifications are computer simulated at the processor pad (inside the CPU package).
  2. Refer to Figure: Maximum Acceptable Overshoot/Undershoot Waveform for description of allowable Overshoot/Undershoot magnitude and duration.
  3. TCH is the minimum high pulse width duration, see DDR5 Signals AC Specifications for details on DDR5 TCH.
  4. For PWRGOOD DC specifications see Processor Asynchronous Miscellaneous I/O DC Specifications.
  5. Refer to Table: Signal Groups for a list of signals under the different signal groups, except for the signals that are explicitly listed on this table.