Scan-Load-Based Dynamic Scan Configuration for ASIC Testing
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Solution Overview
Problem
Existing scan configuration methods, such as MUX-based dynamic scan configurations, require extensive interconnect networks to distribute configuration signals, leading to hardware overhead and potential signal integrity issues, limiting their flexibility and efficiency in reconfiguring scan structures for post-silicon applications like testing and debugging.
Innovation Solution
A scan-load-based dynamic scan configuration that uses the scan-load operation to distribute configuration data to reconfigurable scan cells, eliminating the need for interconnect networks by integrating a pass-through mode and a configuration-set signal to set and maintain scan cell configurations without additional inputs, allowing for flexible reconfiguration of scan structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If MUX-based dynamic scan configuration is used, then scan structure reconfiguration capability is improved, but hardware overhead and interconnect network complexity increase
Solution Approach 1:
The patent extracts and eliminates the interconnect network from the system by using scan-load operation to distribute configuration data directly to scan cells through the existing scan-in path, removing the need for separate configuration signal distribution infrastructure
Solution Approach 2:
The scan-load operation serves dual purposes: it loads test data into scan cells for testing operations and simultaneously distributes configuration data to reconfigure scan cell connections, making the same operation mechanism serve multiple functions
2Adaptability or versatility
If extensive interconnect networks are used for configuration signal distribution, then configuration flexibility is improved, but signal integrity issues and hardware overhead increase
Solution Approach 1:
The patent removes the problematic interconnect network that causes signal integrity issues by using the scan-load operation to directly configure scan cells through the scan-in path, eliminating long configuration signal routes
Solution Approach 2:
The scan-load operation acts as an intermediary mechanism that transfers configuration data from the configuration source directly to scan cells without requiring separate configuration signal lines, using the existing scan data path as the mediator
3Ease of manufacture
If traditional scan configuration methods are used, then manufacturing simplicity is maintained, but post-silicon reconfiguration capability is limited
Solution Approach 1:
The patent introduces dynamic reconfiguration capability to static silicon structures by enabling scan cells to be reconfigured after manufacturing through scan-load operation, allowing the scan structure to adapt to different testing requirements post-silicon
Solution Approach 2:
The patent embeds reconfiguration capability during the manufacturing process by integrating scan cells with configuration storage and scan-load paths, so that reconfiguration functionality is prepared in advance but activated only when needed in post-silicon applications
Data Source
AI summary
A scan-load-based (SLB) dynamic scan configuration reconfigures scan structures via scan-load operation, thereby eliminating interconnect network distributing configuration signals, and employs common scan circuitry identical for designs at mask level and is suitable for ASIC implementations. The architecture includes reconfigurable scan cells, apparatus for distributing configuration data to the reconfigurable scan cells and for determining desired reconfiguration data for each of the reconfigurable scan cells, and a configuration-set (CS) signal. Each of the reconfigurable scan cells has a pass-through (PT) mode in which data input, either a scan-in (SI) or a system-data (SD) of the scan cell, is transparently passed to a scan-out (SO) terminal of the scan cell without requiring a pulse on a shift clock (SC). The configuration-set (CS) signal communicates with each of the reconfigurable scan cells. A pulse on the configuration-set (CS) signal triggers PT Hold latches to capture configuration data from corresponding slave latches, which in turn set configurations of each of the reconfigurable scan cells.