Configurable Interface Circuitry for Network Processor Clock Domain Allocation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional network processors lack flexibility in allocating signal lines of an interface bus to multiple clock domains, leading to restricted functionality and timing disadvantages, such as longer clock insertion delays, and complicating scan vector testing.
Innovation Solution
The network processor incorporates interface circuitry with configurable sampling registers and multiplexers that allow signal lines to be associated with different interface clock domains, enabling flexible configuration and association of signal lines with various clock domains, which can be controlled by software through configuration registers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a common clock is used for all ports, then device complexity is reduced, but adaptability and functionality are severely restricted
Solution Approach 1:
The interface circuitry is segmented into multiple independent clock domains, each capable of operating at different clock rates. This allows different ports to be assigned to different clock domains, enabling flexible clock configuration without requiring a completely separate clock system for each port, thus balancing complexity and adaptability.
Solution Approach 2:
The interface circuitry is designed with multi-functionality to support both common clock operation and independent clock domain operation. The same circuitry can be configured to work with a single clock source for all ports or with multiple independent clock sources, providing universal adaptability across different application scenarios.
2Adaptability or versatility
If multiplexed clocks are used to sample common interface lines, then adaptability is improved, but clock insertion delays increase and device complexity increases
Solution Approach 1:
Instead of using a single multiplexed clock signal that requires time-division switching, the system segments the clock distribution into separate clock domains. Each domain receives its clock signal directly without time-multiplexing, eliminating the clock insertion delays associated with multiplexing while maintaining the ability to support multiple clock rates.
3Adaptability or versatility
If multiplexed clocks are used to sample common interface lines, then adaptability is improved, but scan vector testing becomes more complicated
Solution Approach 1:
The segmentation of the interface circuitry into distinct clock domains with dedicated sampling registers simplifies testing. Each clock domain can be independently tested using scan vectors, avoiding the complex timing and synchronization issues that arise with multiplexed clock systems where multiple clock signals share common interface lines.
Data Source
AI summary
A network processor or other type of processor includes an interface comprising a plurality of signal lines, and interface circuitry adapted to receive clock signals for respective interface clock domains of the processor. The interface circuitry comprises a plurality of sampling registers clocked by respective ones of the clock signals. The interface circuitry is configurable in a variety of different configurations, each providing a different association between designated subsets of the signal lines and the clock domains of the processor.