Hello!
I use multichannel 10bit ADC(ad7812) with serial interface. Channels rfs and tfs tied in singlechannel. SCLK, DIN, DOUT, come on separate pins. I do not use standard spi interface and generate SCLK signal manually. On idea firstly it is necessary to write 10bit word, where we choose channel of measurement. Next rfs-tfs is swiched in reading mode and we read 10bit word with result of the measurement. But i have found a strange bug: ACP return result of previus measurement. So, if we continouslly measure 4 channels in the first we will have result of forth in the second result of first and so on. Now i forced to request each channel two times and this is takes a lot of time. May be you know how avoid this problem? Unfotrunally i have not found any information about this problem at Analog Devices website. Early i used one channel ADC and all was OK. ADC functions you can see below.

unsigned int read_adc(unsigned int channel)
{
unsigned char charray[3]={0,0,0};
unsigned char i;
//control word
unsigned char adc_wseq[10]={
0, //A0
1, //PD1
1, //PD0
0, //Vin
0, //DIFF
0, //CH2
0, //CH1
0, //CH0
1, //CONVST
1 //EXTREF
};
unsigned int buf=0;
//conversion decimal channel to binary
for(i=2;channel!=0;i--)
{
charray[i]=channel % 2;
channel/=2;
}
//insertion channel number to control word
adc_wseq[5]=charray[0];
adc_wseq[6]=charray[1];
adc_wseq[7]=charray[2];


//transmitting control word
rtfs=FALSE; //rfs-tfs in transmit mode
for(i=0;i<10;i++) //transmit a control word
{
SCLK=TRUE;
DIN=adc_wseq[i];
SCLK=FALSE;
}

CONVST=FALSE; // adc in hold mode
CONVST=TRUE;

rtfs=TRUE;//rfs-tfs in receive mode
for(i=0;i<10;i++) //reading a result
{
SCLK=TRUE;
if (DOUT==TRUE) buf=buf+pow(2,9-i);
SCLK=FALSE;
}
return buf;
}//READ_ADC

unsigned int radc(unsigned int channel) // this func. reads each channel two times to avoid a bug
{
read_new_adc(channel);
return read_new_adc(channel);
}
As you can see radc function read request channel two times. It allow to avoid bug but this is not best way.
Thanks for any assistance!
Igor