Multi-Chip Package Independent Testing via Shared Command Pins
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Solution Overview
Problem
Conventional Multi-Chip Packages (MCPs) face challenges in independently testing semiconductor chips that share command pins, as shared command pins prevent individual testing of each chip without affecting the entire package.
Innovation Solution
The MCP system includes a command decoder, data input buffer, command controller, and test controller, which allow each semiconductor chip to decode commands, buffer data, selectively block mode enable signals, and generate test mode signals, enabling independent testing by entering a common test mode and selectively activating masking signals based on data input.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If command pins are shared among multiple semiconductor chips in an MCP, then the number of pins is reduced and manufacturing is simplified, but independent testing of each chip becomes impossible
Solution Approach 1:
The patent segments the testing function by introducing individual data pins for each semiconductor chip while keeping command pins shared. Each chip has its own data input buffer and test control logic that can be independently activated through chip-specific data pins, allowing independent testing without requiring separate command pins for each chip.
Solution Approach 2:
The patent uses data pins as intermediary control signals to activate test modes for individual chips. Instead of using command pins directly for test control, the system mediates through data pins that can selectively enable test functions for specific chips while leaving other chips in normal operation mode.
2Productivity
If command pins are shared among multiple semiconductor chips, then pin count is reduced, but test operations affect the entire package rather than individual chips
Solution Approach 1:
The patent applies local quality by giving each semiconductor chip its own data input buffer and test control logic that can be independently activated. The test mode enable signal can be selectively generated for individual chips based on data received through their respective data pins, allowing localized testing without affecting other chips in the package.
Solution Approach 2:
The patent introduces dynamic control through test mode enable signals that can be selectively activated for individual chips. The system can dynamically switch between normal operation mode and test mode for specific chips based on control signals received through data pins, enabling flexible and selective testing.
Data Source
AI summary
A multi-chip package may include a plurality of semiconductor chips integrated in a single package and sharing one or more command pins. Each of the semiconductor chips may include: a command decoder suitable for decoding a command to generate a buffer enable signal, a mode enable signal, and a mode signal; a data input buffer suitable for buffering data to output internal data, in response to the buffer enable signal and a common test mode signal; a command controller suitable for receiving the mode enable signal to output a test mode enable signal by selectively blocking the mode enable signal based on the internal data and the common test mode signal; and a test controller suitable for generating the common test mode signal and a test mode signal, based on the test mode enable signal and the mode signal.