I got a problem on DE2-TV,I2C_controller

Altera_Forum · ‎12-07-2009

I2C_SCLK begins at SD_COUNTER 4 and ends at SD_COUNTER 30，while I2C_SDAT begins at SD_COUNTER 3 and ends at SD_COUNTER 29.Why don's they transfer data in the same time.

IN addation ,I2C_SDAT also don't write into I2C_SDAT。

The following is partly the program

wire I2C_SCLK=SCLK | ( ((SD_COUNTER >= 4) & (SD_COUNTER <=30))? ~CLOCK :0 );

wire I2C_SDAT=SDO?1'bz:0 ;

always @(negedge RESET or posedge CLOCK ) begin

if (!RESET) SD_COUNTER=6'b111111;

else begin

if (GO==0)

SD_COUNTER=0;

else

if (SD_COUNTER < 6'b111111) SD_COUNTER=SD_COUNTER+1;

end

//----

always @(negedge RESET or posedge CLOCK ) begin

if (!RESET) begin SCLK=1;SDO=1; ACK1=0;ACK2=0;ACK3=0; END=1; end

else

case (SD_COUNTER)

6'd0 : begin ACK1=0 ;ACK2=0 ;ACK3=0 ; END=0; SDO=1; SCLK=1;end

//start

6'd1 : begin SD=I2C_DATA;SDO=0;end

6'd2 : SCLK=0;

//SLAVE ADDR

6'd3 : SDO=SD[23];

6'd4 : SDO=SD[22];

6'd5 : SDO=SD[21];

6'd6 : SDO=SD[20];

6'd7 : SDO=SD[19];

6'd8 : SDO=SD[18];

6'd9 : SDO=SD[17];

6'd10 : SDO=SD[16];

6'd11 : SDO=1'b1;//ACK

//SUB ADDR

6'd12 : begin SDO=SD[15]; ACK1=I2C_SDAT; end

6'd13 : SDO=SD[14];

6'd14 : SDO=SD[13];

6'd15 : SDO=SD[12];

6'd16 : SDO=SD[11];

6'd17 : SDO=SD[10];

6'd18 : SDO=SD[9];

6'd19 : SDO=SD[8];

6'd20 : SDO=1'b1;//ACK

//DATA

6'd21 : begin SDO=SD[7]; ACK2=I2C_SDAT; end

6'd22 : SDO=SD[6];

6'd23 : SDO=SD[5];

6'd24 : SDO=SD[4];

6'd25 : SDO=SD[3];

6'd26 : SDO=SD[2];

6'd27 : SDO=SD[1];

6'd28 : SDO=SD[0];

6'd29 : SDO=1'b1;//ACK

//stop

6'd30 : begin SDO=1'b0; SCLK=1'b0; ACK3=I2C_SDAT; end

6'd31 : SCLK=1'b1;

6'd32 : begin SDO=1'b1; END=1; end

endcase

end

Hope for the answer ，thanks

Altera_Forum · ‎12-10-2009

the first couple of counts sets up the start condition for the write process and the last couple of counts are the end condition. I2C_DAT is the program data coming into this module and I2C_SDAT is the serial data going to the codec. Hope this helps

Altera_Forum · ‎12-10-2009

--- Quote Start ---

the first couple of counts sets up the start condition for the write process and the last couple of counts are the end condition. I2C_DAT is the program data coming into this module and I2C_SDAT is the serial data going to the codec. Hope this helps

--- Quote End ---

Thanks for your help.According to your explanation I understand it.

And I hope you can help me to solve another problem:

wire I2C_SDAT=SDO?1'bz:0 ;

It is the above problem too.It looks like that, the data does not transferred to the slave chip.When the data is "0",the controller writes 0 to I2C_SDAT,but when it is "1",the controller writes "z" to I2C_SDAT ,so writing is shut up. It is about I2C_BUS.

Thank you very much!

Altera_Forum · ‎12-10-2009

I didnt get it myself but you can change it so it either gives '0' or the data bit to be sent. It works either way.

Altera_Forum · ‎12-12-2009

Thank you ,I will have a try.