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Altera_Forum
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10 years ago

Nios SPI read

Hi everybody, I'm using the alt_avalon_spi_command Altera function to write on a DAC and i have problem when i tried to read what i have wrote before. The DAC requiert 1 instruction byte (r/w+7 a...
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Altera_Forum
Icon for Honored Contributor rankHonored Contributor
10 years ago

Hi Galfonz,

I'm using a DAC34H84 of Texas instruments.

The write spi function does not have any problem.

{0x00,0x01,0x8C} ===> 0x00 is the instruction byte (w+adress register); 0x01 is the MSB of the 16 bits of data and 0x8C is the LSB.

So look only this function

void read_dac84h84_spi(){

alt_u8 adress=0x04;

alt_u8 rdata[2];

alt_avalon_spi_command(DAC34_SPI_BASE,0,1,(0x10+ad ress),2,rdata,NULL); arg0=master spi id, arg1= slave spi id, arg2=write lentgh,arg3=write data pointer,arg4=read lentgh,arg5=read data pointer,arg6=flags

printf("Register %d : %X%X\n",adress,rdata);//

return;}

Best regards