Jay Trodden and Don Anderson

This chapter describes HyperTransport flow control, used to throttle the movement of packets across each link interface. On a high-performance connection such as HyperTransport, efficient management of transaction flow is nearly as important as the raw bandwidth made possible by clock speed and data bus width. Topics covered here include background information on bus flow control and the initialization and use of the HyperTransport virtual channel flow control buffer mechanism defined for each transmitter-receiver pair.