On-chip waveform measurement

Patent metadata

Field	Value
Publication number	US-10263606-B2
Application number	US-201715792819-A
Country	US
Kind code	B2
Filing date	Oct 25, 2017
Priority date	Jan 31, 2017
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

A circuit for measuring a transition time of a digital signal may be provided. The circuit comprises a window detector comprising a comparator circuitry arranged for generating a first signal based on comparing said digital signal with a first reference voltage and for generating a second signal based on comparing said digital signal with a second reference voltage. Additionally, the circuit comprises a time-difference-to-digital converter operable for converting a delay between an edge of said first signal and an edge of said second signal into a digital value, said digital value characterizing said transition time of said digital signal.

First claim

What is claimed is:

1. A method for operating a circuit for measuring a transition time of a digital signal, said method comprising
choosing a rising or a falling edge of said digital signal,
setting a lower programmable delay value and an upper programmable delay value to a minimum value each,
define a first reference voltage and a second reference voltage characterizing said transition time of said digital signal,
determining whether a skew sensor is metastable and, on a positive outcome of said determination, save an adjusted step count of said upper and lower programmable delay value
in case of a negative outcome of said determination, selecting either said upper or said lower programmable delay value to be decreased or increased, respectively, before returning to said step of determining whether said skew sensor is metastable.

2. The method according to claim 1 , wherein said determination whether said skew sensor is metastable has a positive outcome if a predefined percentage value of cycles has another value than a predetermined logical value.

Assignees

• IBM

Inventors

• Arp Andreas
• Cilek Fatih
• Koch Michael V
• Ringe Matthias

Classifications

• G04F10/005

  Time-to-digital converters [TDC] (analog-to-digital converters with intermediate conversion to time or phase H03M1/50, H03M1/60) · CPC title

• H03K5/26

  the characteristic being duration, interval, position, frequency, or sequence · CPC title

• H03K2005/00058

  controlled by a digital setting · CPC title

• G01R25/005

  Circuits for comparing several input signals and for indicating the result of this comparison, e.g. equal, different, greater, smaller, or for passing one of the input signals as output signal · CPC title

• H03K5/04 Primary

  by increasing duration; by decreasing duration · CPC title