Method and apparatus for managing timestamps when storing data
AssigneeHewlett-Packard Development Company, L.P.
InventorsTimothe Litt, Richard E. Kessler, Thomas Hummel
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Abstract
A system is disclosed in which an on-chip logic analyzer (OCLA) includes timestamp logic capable of providing clock cycle resolution of data entries using a relatively small number of bits. The timestamp logic includes a counter that is reset each time a store operation occurs. The counter counts the number of clock cycles since the previous store operation, and if enabled by the user, provides a binary signal to the memory that indicates the number of clock cycles since the previous store operation, which the memory stores with the state data. If the counter overflows before a store operation is requested, the timestamp logic may force a store operation so that the time between stores can be determined.
Claims33
An integrated circuit fabricated on a chip, comprising:
- an on-chip logic analyzer including timestamp logic, said timestamp logic includes a timestamp counter that generates a timestamp count value signal indicating the number of clock cycles since a previous store operation;
- an on-chip memory capable of storing data selected by said on-chip logic analyzer;
- wherein the data stored by said on-chip memory is combined with a timestamp field representing the number of cycles since the previous store operation;
- and
- wherein the on-chip logic analyzer generates a store signal when data is to be stored in the memory, and wherein the timestamp counter receives the store signal and resets the timestamp count value.
A system for storing timestamp information together with selected data, comprising:
- a memory device with multiple entries capable of storing a bit field of a predetermined length;
- data selection logic that monitors data, and which selectively stores data to said memory;
- a timestamp counter coupled to said memory for supplying a timestamp value which can be selectively stored with said data in said memory;
- wherein said timestamp value represents the number of clock cycles that have been counted by said timestamp counter since the previous entry was stored in said memory, and wherein said timestamp counter forces a store operation if the timestamp value reaches a predetermined value.
A processor fabricated on a chip, comprising:
- an on-chip logic analyzer including a timestamp counter;
- an on-chip memory capable of storing data selected by said on-chip logic analyzer, said memory having a width of z bits;
- wherein said timestamp counter counts the number of clock cycles since the previous data storage, and generates a timestamp count value of n bits, which can be selectively stored with said data in said memory, and wherein said timestamp counter is capable of forcing storage of data when the timestamp count value reaches a predetermined value.
Dependencies are inferred from the claim text.