Retry Buffer Handling for ePHIT Retransmission as PHITs

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing Mobile Industry Processor Interface (MIPI) Alliance Low Latency Interface (LLI) protocol faces challenges with increased complexity and error rates due to the use of extended PHITs (ePHITs), which require more buffering and are not backward compatible with standard PHITs, leading to higher latency and throughput issues.

Innovation Solution

Storing only PHITs in the retry buffer and using a prior art retry mechanism to retransmit errant ePHITs as PHITs, with sequence numbers hashed using an XOR function to form PA layer CRCs, allowing backward compatibility and reduced complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If extended PHITs (ePHITs) are used to compress multiple DL frames, then data throughput is improved, but retry buffer complexity increases significantly

Engineering Contradiction:

Improvedata throughputVSAvoidretry buffer complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the retry buffer into two separate buffers: one for PHITs and one for ePHITs. This segmentation allows each buffer to be optimized independently, with the PHIT buffer using standard-width entries and the ePHIT buffer using full-width entries, thereby reducing overall complexity while maintaining throughput benefits

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent extracts the problematic complexity by separating ePHIT handling from the standard PHIT retry buffer. By taking out ePHITs into a dedicated buffer structure, the standard PHIT retry buffer remains simple and unchanged, while ePHIT-specific complexity is isolated and managed separately

Inventive Principle:

Principle #2Taking out (Extraction)

2Loss of substance

If ePHITs are used for data transmission, then compression efficiency is improved, but DL error rate increases

Engineering Contradiction:

Improveoverhead reductionVSAvoiderror rate

Core Design Contradiction:

Loss of substanceVSReliability

Solution Approach 1:

The patent applies local quality by using different CRC polynomial degrees for different data types: ePHITs use a 16-bit CRC (lower protection) while PHITs use a 32-bit CRC (higher protection). This localized adaptation of error protection strength matches the actual risk profile of each format, reducing overall error rates while maintaining compression efficiency where applicable

Inventive Principle:

Principle #3Local quality

3Quantity of substance

If retry buffer is organized for ePHIT width, then ePHIT storage is optimized, but PHIT storage becomes sub-optimal

Engineering Contradiction:

ImproveePHIT storage efficiencyVSAvoidPHIT storage efficiency

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The patent merges two previously conflicting storage requirements into a unified dual-buffer architecture. The PHIT buffer and ePHIT buffer operate independently but are managed together by a single retry mechanism, allowing each buffer to maintain optimal entry widths for its specific data type while sharing common control logic

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS9503222B2Differential formatting between normal and retry data transmission

Publication Date: 2016.11.22 QUALCOMM TECHNOLOGIES INC

AI summary

A first frame and a second frame are combined into an extended frame. The extended frame is encapsulated and transmitted over a channel as an extended physical digital. A transmission error notification is received, indicating error in a reception of the transmitted extended physical digital. In response, a re-transmission encapsulates the first frame into a first physical digit, transmits the first physical digit over the channel, encapsulates the second frame into a second physical digit, and transmits the second physical digit over the channel.