Flag-based readout architecture for event-driven pixel matrix array
AssigneeCommissariat A L'energie Atomique Et Aux Energies Alternatives
InventorJosep Segura Puchades
Life of this patent
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Abstract
An event-driven sensor including: a pixel array; a column readout circuit coupled to column output lines of the pixel array, the column readout circuit comprising a plurality of groups of column register cells coupled in series with each other to propagate a first flag signal, wherein each column register cell is configured to activate a column event output signal when it receives the first flag signal while the detection of an event is indicated on the column output line; and a first bypassing circuit for each group of column register cells, the first bypassing circuits being coupled in series with each other to propagate the first flag signal.
Claims11
An event-driven sensor comprising:
- a pixel array;
- a column readout circuit coupled to column output lines of the pixel array, the column readout circuit comprising a plurality of groups of column register cells, each group of column register cells comprising at least two column register cells, each column register cell being coupled to a corresponding one of the column output lines, the column register cells of each group being coupled in series with each other to propagate a first flag signal from a first to a last column register cell of the group, wherein each column register cell is configured to activate a column event output signal when it receives the first flag signal while the detection of an event is indicated on the column output line;
- and
- a first bypassing circuit for each group of column register cells, the first bypassing circuits being coupled in series with each other to propagate the first flag signal, each first bypassing circuit being configured to propagate the first flag signal:
- to the first column register cell of its group if an event is indicated on one of the column output lines coupled to one of the column register cells of the group;
- and
- to a flag output of the first bypassing circuit, bypassing the column register cells of the group, if no event is indicated on one of the column output lines coupled to one of the column register cells of the group.
A method of reading out an event from a pixel of an event-driven sensor, the method comprising:
- propagating, through a series of first bypassing circuits of a column readout circuit, a first flag signal, wherein the column readout circuit further comprises a plurality of groups of column register cells, each group of column register cells comprising at least two column register cells, each column register cell being coupled to a corresponding one of the column output lines, the column register cells of each group being coupled in series with each other to propagate the first flag signal from a first to a last column register cell of the group, wherein each first bypassing circuit is configured to propagate the first flag signal:
- to the first column register cell of its group if an event is indicated on one of the column output lines coupled to one of the column register cells of the group;
- and
- to a flag output of the first bypassing circuit, bypassing the column register cells of the group, if no event is indicated on one of the column output lines coupled to one of the column register cells of the group;
- and
- activating, by one of the column register cells, a column event output signal when it receives the first flag signal while an event is indicated on the column output line.
Dependencies are inferred from the claim text.