| 摘要 |
<p>An improved audio-output device in which a DSP (202) operating under software control emulates a common command interface. The command interface has a set of registers that are made available to the CPU for reading and writing, even if there are no such physical registers available in the device. The audio-output device has a DSP (202) for interpreting and executing commands received from the CPU, a local memory (205) for storing data input to or output from the DSP (202), a bus-interface (BIF) (201) element for coupling the DSP (202) and memory (205) to a system bus (105), and a direct memory access (DMA) element for transferring data between the local memory (205) and the system bus (105). The local memory (205) has an emulation region for emulating a set of registers, and a communication region for transmitting messages between the local memory (205) and the system bus (105).</p> |
