DMA Hardware Acceleration for PPP Frame Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High data rate wireless communication networks require significant processor bandwidth for PPP frame processing, including FCS calculation, octet inspection, and character escaping, which is inefficient and consumes excessive computational resources.
Innovation Solution
Integration of PPP frame processing, including FCS calculation, octet inspection, and HDLC flag insertion, into a DMA module that operates autonomously of the processor, either discretely or in linked-list mode, to free up processor bandwidth for other tasks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If PPP frame processing is performed by software on the processor, then processing accuracy and reliability are maintained, but processor bandwidth is excessively consumed and processing speed decreases
Solution Approach 1:
The patent segments the PPP frame processing function from the main processor software and implements it as a dedicated hardware module within the DMA controller. This segmentation allows the processor to focus on higher-level tasks while the DMA hardware handles octet-by-octet inspection, FCS calculation, and character escaping, thereby resolving the contradiction between processing accuracy and processor bandwidth consumption.
Solution Approach 2:
The patent introduces a specialized PPP processing module as an intermediary between the DMA transfer function and the processor. This intermediary hardware module performs the computationally intensive PPP frame processing operations autonomously, mediating between the need for accurate software-level processing and the requirement for high-speed hardware-level data transfer, thus freeing processor bandwidth while maintaining processing reliability.
2Speed
If PPP frame processing is performed at high data rates, then data transmission speed is improved, but processor load becomes excessive and consumes inordinate share of processor bandwidth
Solution Approach 1:
The patent extracts the energy-intensive PPP frame processing operations (octet inspection, FCS calculation, character escaping) from the main processor and implements them in dedicated DMA hardware. This extraction eliminates the exponential growth of processor energy consumption that would otherwise occur at high data rates, allowing the system to maintain high transmission speeds without excessive processor energy usage.
Solution Approach 2:
The patent implements self-service by enabling the DMA module to autonomously perform PPP frame processing without processor intervention. The hardware module independently inspects each octet, calculates FCS values, performs character escaping, and manages the complete PPP framing process, thereby eliminating the need for continuous processor involvement and reducing energy consumption at high data rates.
3Reliability
If processor is dedicated to PPP frame processing, then processing accuracy is maintained, but overall system performance and efficiency decrease
Solution Approach 1:
The patent replaces the software-based PPP processing mechanism with a hardware-based implementation within the DMA module. This substitution maintains the accuracy and reliability of PPP frame processing (through dedicated hardware logic for FCS calculation and octet inspection) while dramatically improving overall system performance by freeing the processor for other computational tasks and enabling parallel operation of multiple functions.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
PPP frame encapsulation of IP frames - including FCS calculation, character escaping, and HDLC flag insertion - is performed by hardware acceleration circuits within a DMA module as part of a DMA transfer autonomously of a processor. Software may preprocess the IP packets prior to the hardware-accelerated processing. The hardware acceleration in the DMA module may additionally decapsulate PPP frames - including FCS calculation and comparison for error detection, escaped character recovery, and frame boundary detection - to assist in the formation of IP packets. The hardware-accelerated PPP framing may be particularly useful when a mobile terminal provides internet access, through a wireless communication network over packet data channels, to an attached peripheral device, such as a computer.