I'm using DAC8562 to generate ramp for VCO. But I encountered some problems with the SPI coding,
I did the power up and internal reference command before sending the data. But didn't see the 2.5V at the VREFIN/VREFOUT pin, and nothing output. Is there any standard process(command sequence) before the data sending?
this is the hardware connection, for the code:
#define CMD_WRITE_IRN ((0x00)<<19) // Write to input register 'n'
#define CMD_SOFT_LDAC ((0x01)<<19) // Software LDAC, update DAC register 'n'
#define CMD_WRITE_IRN_UPD ((0x02)<<19) // Write to input register 'n' and update all DAC registers
#define CMD_WRITE_IRN_UPDN ((0x03)<<19) // Write to input register 'n' and update DAC register 'n'
#define CMD_DAC_PWR_MODE ((0x04)<<19) // Set DAC power up/down mode
#define CMD_SOFT_RST ((0x05)<<19) // Software reset
#define CMD_SET_LDAC ((0x06)<<19) // Set LDAC registers
#define CMD_SET_IREF ((0x07)<<19) // Enable/disable internal reference
//for initialize the dac:
//software reset after power on
dac_initTxBuffer[0] = CMD_SOFT_RST | 0x1;
//internal reference enable
dac_initTxBuffer[1] = CMD_SET_IREF | 0x1;
//LADC software configure
dac_initTxBuffer[2] = CMD_SET_LDAC | 0x3;
send(dac_initTxBuffer);
for(i=0;i<SPI_BUFFER_SIZE;i++)
{
spiTxBuffer[i] = CMD_WRITE_IRN_UPD | ADDR_AB | (i<<4);
}
send(spiTxBuffer);
