Switching the ADC channels in TI MSC1212Y5

Hi all,

I am using Texas instruments MSC1212Y5 controller at 25Mhz for Data acquisition system in which 2 analog channels are used for Data acq. But the problem is that i can get o/p when I enable only one channel in my code. If I enable both channels I am getting o/p of only channel 1 ..which is default channel. I am using ADMUX registers properly to switch the channels.Like ADMUX=0x08..for channel AIN0 and ADMUX=0x28 for channel AIN1. The TI user guide says that, when using multiple channels the position of ADMUX switching reg should synchronized with data rate. I have tried all options but the problem persists. At the same time . I am using start trigger, .i.e. if i am using any character(from hyper terminal) to trigger the channel switching manually then it is working properly..what could be problem ??? Please help me..