voltage I/O & system timer

Hello,

I have two questions : I don't know why calling alt_timerstamp_start() generates ticks count at 50 MHz. Although I initialized the Timestamp timer (HIGH_RES_TIMER) at 1ms/tick in SOPC Builder. I thought that the tick count could be incremented at each 1ms interval.

My second question is about the I/O voltage. I'm using Stratix 1S10 dev. board and I can use the prototype header to test a small design. I would like to send TTL (0-5V) voltage to the dev. board but I don't which IO to choose.

Best regards

Christian