ATE Gating Circuit for Source Synchronous Device Testing
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Solution Overview
Problem
Conventional automated test equipment (ATE) systems face inaccuracies when testing source synchronous devices due to interference from edges generated on the strobe line while driving data, leading to incorrect determination of device functionality.
Innovation Solution
The implementation of a driver circuit, receiver circuit, and gating circuit in the ATE that selectively passes a received strobe signal based on a drive enable signal, generating a gated strobe signal to accurately synchronize data reception from semiconductor devices, thereby preventing incorrect data sensing during testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the ATE couples the strobe line to a control input to control receiver timing, then the receiver can be synchronized with data signals, but edges generated on the strobe line while driving data cause interference and incorrect data sensing
Solution Approach 1:
The patent introduces a gating circuit as an intermediary between the strobe line and the receiver control input. This gating circuit selectively passes or blocks edges on the strobe line based on the state of a drive enable signal, preventing harmful edges generated during data driving from reaching the receiver and causing incorrect sensing, while still allowing valid strobe edges to synchronize data reception.
2Ease of operation
If the ATE uses a driver circuit to generate strobe signals on the strobe line, then data transmission timing can be controlled, but edges generated during driving interfere with data reception sensing
Solution Approach 1:
The patent implements preliminary action by using the gating circuit to block harmful edges on the strobe line before they can reach the receiver and cause incorrect data sensing. The gating circuit is controlled by a drive enable signal that anticipates when harmful edges will be generated during data driving, and proactively prevents them from affecting the receiver, thereby maintaining test result accuracy while preserving strobe signal control capability.
3Reliability
If the ATE processes signals from the DUT and ignores signals transmitted on the data line by the ATE, then test results reflect DUT functionality, but this requires discarding data values sensed in response to strobe signals transmitted from the ATE
Solution Approach 1:
The patent extracts and removes harmful edges from the strobe line signal using the gating circuit, allowing the receiver to process only valid strobe edges that correspond to actual DUT data transmission. This prevents the receiver from sensing spurious data values that would need to be discarded, thereby maintaining test result validity while reducing the time loss associated with discarding invalid sensed values.
Data Source
AI summary
Circuitry and methods of operating the same to strobe a DQ signal with a gated DQS signal are described. Some aspects are directed to a gating scheme to selectively pass a received strobe signal such as a DQS strobe signal based on a state of a drive enable (DE) signal in a drive circuit in the ATE, such that edges generated by the drive circuit are prevented from mistakenly strobing a received data signal such as a DQ signal.