Handling of Hardware Errors Detected by a Line Scanner in a Communication Controller
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
In a communication controller such as that shown in the drawing, line scanners scan the lines sequentially and process each line adequately. If a hardware error is detected on one line, it has to be signalled to the communication scanner processor (CSP) which controls the line. According to this proposal, this is done without slowing down the normal processing of lines which are not in error. In order to signal a hardware error, the scanner makes an interrupt request to the microprocessor at the normal working level (level 2). Thus, the microprocessor does not have to handle a level O interrupt request (highest priority level), which saves processing time. Furthermore, the scanner uses the circuits which are provided to signal a normal operation event. In the scanner, two external registers are used to this end.