Thanks Jerson,
I found it is not setup time of CD4052 making problem.
I have now connected the inputs directly to MCP3202 Ch0 & Ch1.
So byspassed all selection problems. Still it is same problem.
I figure out that it is setup of 3202.
The start bit as loaded by ADSTRT routine isnt loaded.
So MCP takes the Single/differential bit coming after that as
start bit. So in Ch0 code the next bit is 0 and makes ADC as
differential. But bias level at ch0/ch1 is midway and ADC cant
take -In more than 100mV so it seems that ADC gets latched in
differential mode till power is there.
Now interesting part is that when checking Ch0 I get output
(Ch0-Ch1)^2 summed for 64 times and then finally divided by 64
and then get square rooted. Before squaring the value of midpoint is substracted so it becomes (Ch00^2 only as Ch1 is at
midpoint. So I get the value of Ch1 correctly. But when checking
Ch1 there is something like offset value of Ch1 that makes sum = Ch0^2 + small value. So I get the output as Ch0/8 + some offset value !!!!
So now I am checking what is happening to start bit of MCP and kick it start !
Thanks everybody,
psd