Programmable InfiniBand switch

A method of changing the speed of operation to 1× in a switch for use with an InfiniBand network, the method comprising:

• upon receipt of a SOP discarding all lanes of data;
• in a second cycle registering a first byte of a first word;
• in a third cycle registering a second byte of the first word while maintaining the first byte;
• in a fourth cycle registering a third byte of the first word while maintaining the first and second byte;
• in a fifth cycle receiving a fourth byte of the first word and combining the first, second, third and fourth byte in a buffer for transfer to a crossbar;
• and
• in a sixth cycle in registering a first byte of a second word.

A method of changing the speed of operation to 4× in a switch for use with an InfiniBand network, the method comprising:

• upon receipt of a SOP discarding all lanes of data and registering a first, second and third bytes of a first word;
• in a second cycle receiving the fourth byte of a the first word, combining the first, second, third and fourth byte of the first word in a buffer for transfer to a crossbar and registering a first, second and third bytes of a second word;
• and
• in a third cycle receiving the fourth byte of a the second word, combining the first, second, third and fourth byte of the second word in a buffer for transfer to a crossbar and registering a first, second and third bytes of a third word.

A switch for use with an InfiniBand network, the switch comprising:

• a crossbar that redirects packet based data based on a forwarding table;
• a least one port that receives data from the crossbar and selectively transfers that data to a network at 1×, 4×, and 12× speeds;
• and
• a state machine that controls the changing of the speed of operation of the port.