Diagnostic/Videotex Clocking Technique
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Jan-31
The design of the IBM RT PC Multi-Protocol Communications Adapter uses a communications controller chip that has two independent channels. Each channel contains a Baud Rate Generator (BRG) used to generate clock signals for transmission and reception of data. This method provides a hardware path such that the BRG output from one channel can be gated into the clock input of the opposite channel and provides for effective diagnostic capability as well as a functional option that can be used in a real application. The method uses an external gating structure, shown above, to provide the output clock signal of one channel to be connected to the input clock signal of the opposite channel.