ADC Comparator Triggering for CPU-Free Interrupt Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing analog-to-digital converter systems require frequent intervention by the central processing unit to determine if conditions for generating an interrupt signal are present, leading to inefficiencies and wasted processing time when conditions are not met.
Innovation Solution
A programmable trigger level configuration where digitized signals from an analog-to-digital converter are stored in buffer/registers and compared with preselected values using a comparator unit, generating an interrupt signal only when the appropriate condition is detected, thereby reducing the need for central processing unit intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the central processing unit frequently checks conditions to determine whether to generate an interrupt signal, then the system can respond to conditions, but the processing time is wasted when conditions are not met
Solution Approach 1:
The patent applies preliminary action by pre-comparing the digitized signal with the trigger level value before an interrupt is requested. The comparator unit continuously monitors the signal level and prepares the interrupt request in advance, so that when the condition is met, the interrupt is generated immediately without requiring the central processing unit to repeatedly check the condition. This eliminates wasted processing time while maintaining reliable condition detection.
2Measurement precision
If the central processing unit is involved in every comparison operation, then accurate comparison results are obtained, but the central processing unit operation is disrupted
Solution Approach 1:
The patent extracts the comparison function from the central processing unit and implements it independently in the comparator unit. The comparator unit is a separate hardware component that performs the comparison between the digitized signal and trigger level value autonomously, generating interrupt requests directly to the display controller. This extraction maintains accurate comparison results while freeing the central processing unit from continuous intervention, thereby improving its operational efficiency.
Solution Approach 2:
The patent introduces an intermediary comparator unit that mediates between the analog-to-digital converter and the display controller. This intermediary component handles the comparison operation and interrupt request generation, allowing the central processing unit to focus on its primary functions. The comparator unit acts as a dedicated mediator that ensures accurate comparisons without disrupting central processing unit operation.
3Reliability
If continuous monitoring of signal levels is performed, then conditions are detected reliably, but processing resources are consumed continuously
Solution Approach 1:
The patent implements periodic action through the continuous operation of the comparator unit that monitors the digitized signal level against the trigger level value. Rather than requiring periodic intervention from the central processing unit, the comparator unit continuously performs the comparison operation in the background and only consumes significant processing resources when an interrupt request is actually generated. This approach maintains reliable condition detection while optimizing energy consumption by avoiding continuous central processing unit involvement.
Data Source
AI summary
In response to a selected analog applied to the input terminal of an analog-to-digital converter, the digitized output signal is stored in a buffer/register. In making a comparison with a predetermined value, a second buffer/register stores either a preselected value or a second digitized signal. A comparator is coupled to the first and the second buffer/register to provide the result of a comparison. In this manner, the central processing unit is not involved in the comparison testing procedure.