On Thu, 19 Oct 2000, Alan McIvor wrote: > Hi, > > Does anybody have any details on how to use and interpret the > RISC_STATUS bits inside the BT878? This and other areas aren't covered > very well in the Data Sheets. The data sheets mention that there is a > Technical Reference Manual and a Programmer's Guide but whenever I > request them from Conexant I get a copy of the Data Sheet. Do they > actually exist? I think how it works is that each RISC instruction has a set of bits, which can set or clear each of the risc status bits. There are 4 status bits, in the interrupt status register. Each risc instruction has 8 bits which control them. Four of the eight bits, if set to 1, will cause the status bit to be cleared, the other four will cause the corresponding status bit to be set. I think the idea is so that you can tell why an interrupt has occurred, e.g. even VBI finished, odd field decoded, etc.
