參數(shù)資料
型號: HD40A4668
廠商: Hitachi,Ltd.
英文描述: Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit(帶雙音多頻電路的低電壓微計(jì)算機(jī))
中文描述: 低電壓如同在微機(jī)芯片的DTMF產(chǎn)生電路(帶雙音多頻電路的低電壓微計(jì)算機(jī))
文件頁數(shù): 91/142頁
文件大?。?/td> 894K
代理商: HD40A4668
HD404669 Series
91
DTMF Generation Circuit
The MCU provides a dual-tone multifrequency (DTMF) generation circuit. Figure 69 shows a block
diagram of the DTMF circuit. A DTMF signal consists of two sine waves corresponding to the numbers
and symbols on a telephone keypad. DTMF signals are used to access telephone switching equipment.
Figure 70 shows the DTMF frequency matrix.
The OSC clock (400 kHz, 800 kHz, 2 MHz, 3.58 MHz, 4 MHz, 7.16 MHz, or 8 MHz) is changed into
seven clock signals through the division circuit (1/2, 1/5, 1/9*, 1/10, 1/18*, and 1/20). The DTMF circuit
uses one of the seven clock signals, which is selected by the system clock select register 1, 2 (SSR1: $029,
SSR2: $02A) depending on the OSC clock frequency. The DTMF circuit has transformed programmable
dividers, sine wave counters, and control registers.
The DTMF generation circuit is controlled by the following three registers.
相關(guān)PDF資料
PDF描述
HD40A4669 Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit(帶雙音多頻電路的低電壓微計(jì)算機(jī))
HD404668 Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit(帶雙音多頻電路的低電壓微計(jì)算機(jī))
HD404669 Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit(帶雙音多頻電路的低電壓微計(jì)算機(jī))
HD407A4669 Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit(帶雙音多頻電路的低電壓微計(jì)算機(jī))
HD404719FS Five timer/counters
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
HD40A4668H 制造商:HITACHI 制造商全稱:Hitachi Semiconductor 功能描述:Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit
HD40A4669 制造商:HITACHI 制造商全稱:Hitachi Semiconductor 功能描述:Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit
HD40A4669H 制造商:HITACHI 制造商全稱:Hitachi Semiconductor 功能描述:Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit
HD40L4818H 制造商:Renesas Electronics Corporation 功能描述:
HD40-M 制造商:Tamura Corporation of America 功能描述: