Method and apparatus for the addition and removal of nodes from a common interconnect

An electronic system comprising:

• a first component;
• a second component;
• an interconnect coupled to the first and second components, the interconnect comprising:
• a first node coupled to the first component;
• a second node coupled to the first node and the second component, wherein the interconnect is initially configured to include the first and second nodes;
• and
• a third node that is coupled to the interconnect after the interconnect is initially configured, wherein the first node initiates a new connect handshake with the third node by transmitting a first signal to the third node, the first node signaling that the third node has been added to the interconnect if the third node responds to the first signal by transmitting a second signal, the first node causing the interconnect to be reconfigured if the third node transmits a third signal in response to receiving the first signal

A serial bus comprising:

• a plurality of nodes including a first node;
• at least one point-to-point link, each point-to-point link being coupled between two nodes, wherein the serial bus is initially configured to include the plurality of nodes;
• and
• a second node coupled to the first node that is added to the serial bus after the serial bus is initially configured, the first node transmitting a first signal to the second node in response to detecting addition of the second node to the serial bus, the first node signaling addition of the second node to the serial bus if the second node responds to the first signal by transmitting a second signal, the first node requesting a bus reset if the second node transmits a third signal.

A serial bus comprising:

• a plurality of nodes including a first node, wherein the serial bus is initially configured to include the plurality of nodes;
• at least one point-to-point link, each point-to-point link being coupled between two nodes, wherein each point-to-point link includes at least one pair of differential signal lines including an A line and a B line, each differential signal line capable of being in a 1 state, a 0 state, and a Z state;
• and
• a second node coupled to the first node via a second point-to-point link, the second node being added to the serial bus after the serial bus is initially configured, the first node transmitting a first signal having a value of AB=1Z to the second node via the second point-to-point link in response to detecting addition of the second node to the serial bus, the first node signaling addition of the second node to the serial bus if the second node responds to the first signal by transmitting a second signal having a value of AB=0Z to the first node via the second point-to-point link, the first node requesting a bus reset if the second node transmits a third signal having a value of AB=1Z.

A method for adding a new node to a previously configured serial bus comprising the steps of:

• detecting addition of the new node to the serial bus by a first node that is coupled to the new node by a point-to-point link;
• transmitting a YOU ARE MY CHILD signal by the first node to the new node in response to detecting the addition of the new node;
• transmitting a YOU ARE MY PARENT signal by the new node to the first node in response to receiving the YOU ARE MY CHILD signal if the new node has only one connected port;
• signaling addition of the new node to the serial bus by the first node if the YOU ARE MY PARENT signal is detected by the first node;
• transmitting a YOU ARE MY CHILD signal by the new node to the first node if the new node has more than one connected port;
• and
• requesting a bus reset by the first node if the new node transmits a YOU ARE MY CHILD signal.

A method for removing a first node from a previously configured serial bus comprising the steps of:

• detecting by a second node that the first node has been removed;
• requesting control of the serial bus by the second node;
• granting control of the serial bus to the second node;
• transmitting a NODE_DETACHED_ALERT packet by the second node indicating removal of the first node.

A node for use in an electronic system interconnect comprising:

• at least one port including a first port operative to transmit and receive data when electrically connected to another node;
• a first circuit coupled to the first port operative to detect when an electrical connection is made between the first port and a second node;
• and
• a second circuit coupled to the first port operative to detect how many ports are connected to transmit and receive data after the electrical connection is made between the first port and the second node,
• wherein the node is operative to initiate a new connect handshake with the second node by transmitting a first signal via the first port if the node has more than one connected port, the node being operative to wait for the second node to initiate the new connect handshake by transmitting the first signal to the node if the node has only one connected port, the node transmiting a reset request if the node and the second node contemperaneously assert the first signal.

A method for building a topology map of an interconnect comprising the steps of:

• transmitting a request packet to a first node by a topology manager node, the request packet specifying that the first node is to identify itself;
• receiving the request packet by the first node;
• transmitting a first identity packet by the first node in response to the request, the first identity packet specifying a bus address of the first node;
• receiving the first identity packet by the topology manager node;
• and
• identifying a location of the first node in the interconnect by the topology manager.

A node for use in an electronic system interconnect, comprising:

• a first port operative to transmit and receive data via the serial bus;
• a first circuit coupled to the first port operative to detect receipt by the first port of a first identity request packet addressed to the node;
• and
• a second circuit coupled to the first circuit and the first port, the second circuit operative to transmit a first identity packet via the first port if a first identity request packet is received, the first identity packet specifying a bus address of the node.