I have not heard of anyone needing more than one accelerometer, but I am assuming you are talking about a standard 3-axis chip.
If you want to use more than one 3-axis chip, then I am very curious about your application/idea.
Conceptually, all you need is enough A/D ports on your PSOC to do the basic interface. As I recall, there are at least twelve on the board, so you should be able to make it work.
in this design I connected 7 gyro's and 7 accelerometers to one microcontroller:)
I used SPI for that, with chip selects.
The reason for choosing SPI was that we needed to get the data within a certain time after a synchronisation trigger, and SPI is much faster than I2C. The MMA455L has an address pin, so you could easily connect two of these to one I2C bus.
I have to admit, this is an area that I only spent a limited time working on projects. So in my mind, one accelerometer was plenty, but now I can see a much larger world where they could be employed. Its always a good day to learn something new.
