mylim

Problem with MC9S08AW60 I2C with Built-in vol ctrl Amplifier

Discussion created by mylim on Aug 21, 2007
Latest reply on Sep 6, 2007 by mylim
I’m using freescale MC9S08AW32 MCU with i2c port to interface with an NSC LM49270 audio amplifier with built-in vol ctrl. 
I can't seem to see my data being transmited over the scope & couoldnt control the amplifier.

What I’ve done is as follow;
1.                   Pull up both SDA & SCL line.
2.                   code : (which you may ignore the code portion but only the descriptions I left to indicate my process)
Code:
;--------------------
;LM49270 Vol Ctrl
;--------------------
i2cvol         bclr   IIC1C_TXAK,IIC1C         ;
               lda    IIC1C
               ora    #$30                     ;start
               sta    IIC1C
          
               mov    #I2CADR,IIC1D            ;send slave address(W)
               brclr  IIC1S_TCF,IIC1S,*
               brset  IIC1S_RXAK,IIC1S,*       ;wait for ACK from slave           

               lda    I2CDTA                   ;data to be transmited
               sta    IIC1D                    ;send data
               brclr  IIC1S_TCF,IIC1S,*
               brset  IIC1S_RXAK,IIC1S,*       ;wait for ACK from slave
          
               bclr   IIC1C_MST,IIC1C          ;generate stop
               rts

 
The LM49270 is a write only i2c which it doesn’t’ have a read register for me to read & confirm the data sent.
I've also attached the datasheet as below.
 
3.            I2C configuration:
               SCL = 25kHz
               SDA Hold time = 10us
               IIC1F = 0x87
               IIC1C = 0x90
              
           
Could you please advice & let me know asap.
Thanks.
mingyee



Message Edited by mingyee on 2007-08-21 01:38 PM

LM49270.pdf

Message Edited by t.dowe on 2009-09-22 09:41 AM

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