| 摘要 |
PCT No. PCT/GB93/00512 Sec. 371 Date Sep. 8, 1994 Sec. 102(e) Date Sep. 8, 1994 PCT Filed Mar. 11, 1993 PCT Pub. No. WO93/18585 PCT Pub. Date Sep. 16, 1993.A digital controller provides digital signals to audio modules; the digital signals include both clock signals and data. All of the logic circuits of the controller and of the modules are clocked on the receipt of a rising edge. However, to avoid interference from regular clock pulses, the clock pulses are altered to have a variable mark-space ratio which means that the clock pulses arrive at random times and have random widths and thus appear to be randomized. Use of randomized clock signals can avoid tones appearing in an audio system, and also avoids interference effects in other electrical systems. The use of randomized clock signals is particularly helpful when designing digital circuits which meet current regulations controlling electromagnetic emissions.
|
