51 Research and Design, Electronic Engineers website - Embedded Systems, MCU, DSP, EDA, Test and Measurement, Components, Communications, Power, Microelectronics, Semiconductors

Wednesday, October 15th, 2008 at 21:20 | No comments

Categories: Communication Networks

Tags: DTMF

Short Content:     Abstract: Summarizes basic principle which the DTMF signal produces, proposed that uses SPCE061 the chip the D/A port and uses the I/O port to simulate D/A to produce the DTMF signal two kinds to realize the plan, and realizes the plan through the experiment and the simulation to two kinds to carry on the contrastive analysis. The experiment proved that because the D/A precision is high, uses D/The output the DTMF signal quality to use I/O the resistance network ...

Friday, September 19th, 2008 at 23:07 | No comments

Categories: SCM

Tags: 80C31, DTMF, FSK, short information, telephone

Short Content:     This article has given one kind take 80C31 as the master control CPU fixed-line telephone short information terminal design, explained the fixed-line telephone short information terminal design method and each part of principle of work from the system software and hardware two aspects. Regarding difficulty which meets in the development, like the CAS sound examination, FSK information's processing and questions and so on LCD Chinese character character display have carried on the elaboration with emphasis. Key word: ...