spi Chip select

I am attempting to read a mcp3208.  I have a logic analyzer hooked up that shows no activity on the CS pin.  Do I have to hand drive this?  If so, what in the world is the RP setting and stuff for the CS pin? 

I guess I should be more specific.  I have set the correct rpor for my CS and also the trisbit.  There is no activity on the CS pin.

Ok, what is the purpose of the selectable output sources (page 125 of the manual for the pic24f gb series) Output function 9?  (ss1out - spi1 slave select output) in the rp output mapping

I have been trying to create my own signal, and am unable to properly frame the CS signal for the 3208.  What is a good start and stop sync?  I have been trying this

void InitMCP3208(void){
RPINR20bits.SDI1R=40;// set up rp pin 40 to DI
RPOR10bits.RP21R=7;//set up rp21 to DO
//RPOR13bits.RP26R=9;//set up rp26 to CS
RPOR9bits.RP19R=8;//set up rp19 to CKS
SPI1CON1=0b0000000101111010;
SPI1CON2bits.SPIBEN=1;//enhanced buffer
SPI1STATbits.SPIEN=1;//enable spi port
SPI1STATbits.SISEL=0b101;
//SPI1CON1bits.MSTEN=1;//Master mode
TRISGbits.TRISG7=0;
LATGbits.LATG7=1;

SPI1CON1bits.PPRE=0b10;//clock div 4 = 2 mhz
SPI1CON1bits.SPRE=0b111;//no secondary prescale

SPI1STATbits.SPIROV=0;//clear overflow flag
}



int    readchannel(char channel){
    int reading;
    char command1,command2;
    //while(SPI1STATbits.SRMPT==0);//wait until previous is finished
    LATGbits.LATG7=0;
    command1=channel&0b111;//clear spurious request
    command1=command1>>2;//set for sending
    command1=command1 | 0b110;//add start and signal bit
    SPI1BUF=command1;//send on its way   
    command2=channel&0b11;//clear spurious requestb
    command2=command2<<6;//set for sendind
    SPI1BUF=command2;
    SPI1BUF=0;//send empty request
    while(IFS0bits.SPI1IF==0);//wait until is finished
    reading=SPI1BUF;//read to clear first
    reading=SPI1BUF;//top byte
    reading=(reading<<8)+SPI1BUF;//bottom byte
    LATGbits.LATG7=1;
    IFS0bits.SPI1IF=0;
    reading=reading&0b111111111111;
    return reading;
   
}

Here is a reference on framed SPI. As you can see there is no inherent CS. Just a short pulse at the start of each frame. No way to select between multiple devices. I guess that’s still done manually using a CS pin. Anyway, I couldn’t find anything to suggest the MCP3208 operates in framed mode.

http://dkc1.digikey.com/us/en/tod/Microchip/dsPIC30F_SerialCommSPI_NoAudio/Serial_Communications_using_the_dsPIC30F_SPI_noaudio.swf

Want some sample code? Go here:
http://www.reesemicro.com/Home/pic24-software-library-collection
Download the libraries. In ”chap10” you will find several SPI examples. The simplest is probably ”mcp41xxx.spi_pot.c”. Then look at “spi.h” in “include” and “pic24_spi.c” in “common” to complete a basic project.