Interfacing the ADS1213 can be a little complex, due to the flexibility of the device. You really must read the datasheet carefully, page 25 onwards and particularly the discussion of master and slave modes on page 29.
The chances are that you will want to use it in slave mode. That will probably yield a lower data throughput, but your MCU probably could not keep up with the ADS1213 in master mode!
It really depends what you want to do. You do know that the most critical aspect of your design will be the minimisation of noise around the ADS1213? A 24-bit ADC will show up everything that is not right with the circuit, power supply, layout and shielding and if you don't get it right, you might as well have used a 16-bit part. That will be much harder than working out the interface details.