Modem Line Change Detection Reporting Technique
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
A method is described which off-loads a main processor from having to sample the state of modem lines, detect valid changes in those lines, and interrupt if any change or lack of a change is detected. Micro-processor technology today is allowing more and more software functions to be performed directly on adapter cards. This has two effects: 1) it off loads the main processor from having to do that function, and 2) it makes the interface between the main processor and the auxiliary micro-processor significantly more complex. The problem arises in how to maximize the function performed by the auxiliary processor with a minimum of data exchange between the two processors. In data communication, where the data exchange is via a modem, there are several control and response lines that the computer must monitor.