DTMF Generator Code for MT8888 Interface with 80C51

Discussion in 'Embedded Systems and Microcontrollers' started by prevravanth, Jun 28, 2007.

  1. prevravanth

    Thread Starter New Member

    Dec 29, 2006
    8
    0
    Hi,

    I am trying to develop PC based Dialler using MT8888 Transreceiver interfaced with 80C51.

    Can you give source code in C how to interface the MT8888.

    Specially I donot know how select the Control Register CRA & CRB bits

    If there any example code in c please suggest me

    Thanks
    Prev Ravanth
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,136
    1,786
    CRA and CRB are both at the same address. You need to read the datasheet carefully. Here is the appropriate excerpt
    Code ( (Unknown Language)):
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    3. [FONT=Arial][SIZE=2]The microprocessor interface provides access to five[/SIZE][/FONT][LEFT]
    4. [SIZE=2][FONT=Arial]internal registers. The read-only Receive Data[/FONT][/SIZE]
    5. [SIZE=2][FONT=Arial]Register contains the decoded output of the last[/FONT][/SIZE]
    6. [SIZE=2][FONT=Arial]valid DTMF digit received. Data entered into the[/FONT][/SIZE]
    7. [SIZE=2][FONT=Arial]write-only Transmit Data Register will determine[/FONT][/SIZE]
    8. [SIZE=2][FONT=Arial]which tone pair is to be generated (see Table 1 for[/FONT][/SIZE]
    9. [SIZE=2][FONT=Arial]coding details). Transceiver control is accomplished[/FONT][/SIZE]
    10. [SIZE=2][FONT=Arial]with two control registers (see Tables 6 and 7), CRA[/FONT][/SIZE]
    11. [SIZE=2][FONT=Arial]and CRB, which have the same address. A write[/FONT][/SIZE]
    12. [SIZE=2][FONT=Arial]operation to CRB is executed by first setting the[/FONT][/SIZE]
    13. [SIZE=2][FONT=Arial]most significant bit (b3) in CRA. The following write[/FONT][/SIZE]
    14. [SIZE=2][FONT=Arial]operation to the same address will then be directed[/FONT][/SIZE]
    15. [SIZE=2][FONT=Arial]to CRB, and subsequent write cycles will be directed[/FONT][/SIZE]
    16. [SIZE=2][FONT=Arial]back to CRA. The read-only status register indicates[/FONT][/SIZE]
    17. [SIZE=2][FONT=Arial]the current transceiver state (see Table 8).[/FONT][/SIZE]
    18.  
    19. [/LEFT]
    20.  
     
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