I think that 1Mbps is speed of sample and hold. It is mean that you can use ADC with sample's speed 1Mbps to convert accuraly a sign which have maximize frequency <=0.5Mbps. It is match with Nyquist theory.
1 mega (or is it million?) samples per second. That's the max of what the A/D is speced to do. However, according to nyquist theorem, 1MSPs can detect signals up to a maximum frequency of half that. Google around for it if you do not have any knowledge on signal theory.
I m sure... if they are saying that the ADC is of 1MSPS.... it wont go upto that... thats for sure.... and performance will not be good at 1MSPS....
so take care fo that...
Previopusly I also found the same problem with 100MSPS ADC