Receiving RS485 data

Is it possible to use the Arduino to detect a 5MBaud RS485 data signal?
I could use a level shifter like the Max485 chip to convert to TTL levels, but is the Arduino fast enough to register a new bit every 200ns? And if so how would it roughly be done?
Help much appreciated

According to the datasheet (page 203) the maximum baud rate for a 16 MHz processor is 2 Mbps.

I think you're shit out of luck hairbair, even if the hardware was up to the job you would probably have trouble processing the data unless the overall throughput was low.

Maybe use an external UART. How much data is there? There are UARTs around with 64 and 128 bytes of hardware FIFO, if they go to 5MBps that might get you out of trouble.

Also look at the Due, I've not checked but it may be capable of these speeds.