1. A controller for use in a power converter having an energy transfer element with an input side that receives an ac line, and an output side that delivers an output signal to a load, a power switch being coupled to a primary winding of the energy transfer element for regulating a transfer energy of the output signal delivered to the load, the controller comprising:
an input for receiving a control signal;
comparator circuitry that compares the control signal to a first, second, and third reference signals, the comparator circuitry respectively outputting first, second, and third comparator output signals,
drive circuitry coupled to receive the first, second, and third comparator output signals, the drive circuitry outputting a pulsed drive signal responsive to the first, second, and third comparator output signals, the pulsed drive signal being coupled to control switching of the power switch,
wherein when the control signal is within a first range of values the output signal delivered to the load is regulated at a certain value, when the control signal is within a second range of values the output signal delivered to the load is limited to a maximum value, and when the drive signal is within a third range of values switching of the power switch is disabled.
2. The controller of claim 1 wherein the first range of values corresponds to a closed loop mode of operation.
3. The controller of claim 1 wherein the second range of values corresponds to a limiting mode of operation.
4. The controller of claim 1 wherein the third range of values corresponds to a protection mode of operation.
5. The controller of claim 1 wherein the third range of values is greater than the second range of values.
6. The controller of claim 1 wherein the second range of values is greater than the first range of values.
7. The controller of claim 1 wherein the comparator circuitry further compares the control signal to a fourth reference signal and outputs a fourth comparator output signal to the drive circuitry, wherein when the control signal is within a fourth range of values a pulse width modulation (PWM) dimming operation is implemented with respect to the output signal delivered to the load.
8. The controller of claim 7 further wherein the fourth range of values corresponds to an external command mode of operation.
9. The controller of claim 7 further wherein the fourth range of values is greater than the second range of values.
10. The controller of claim 1 wherein the comparator circuitry further compares the control signal to a fourth reference signal and outputs a fourth comparator output signal to the drive circuitry, wherein when the control signal is within a fourth range of values a pulse width modulation (PWM) dimming operation is implemented with respect to the output signal delivered to the load.
11. The controller of claim 1 wherein the comparator circuitry comprises first, second, and third comparators coupled to receive the first, second, and third reference signals, and output the first, second, and third comparator output signals, respectively.
12. The controller of claim 1 wherein the first second, and third comparators are each voltage comparators.
13. The controller of claim 1 wherein the first, second, and third comparators are each current comparators.
14. A controller for use in a power converter comprising:
an input for receiving a control signal; and
a circuit coupled to receive the control signal and output a drive signal responsive thereto, the drive signal being coupled to control a power switch that regulates an output signal delivered to a load of the power converter,
wherein when the control signal is less than a first threshold the power converter operates in a regulation mode with the output signal delivered to the load being regulated at a certain value, when the control signal is between the first threshold and a second threshold the power converter operates in a limiting mode with the output signal delivered to the load being limited to a maximum value, and when the control signal is greater than a third threshold the power converter operates in a protection mode with the power switch being latched off.
15. The controller of claim 14 wherein the third threshold is greater than the second threshold.
16. The controller of claim 14 wherein the second threshold is greater than the first threshold.
17. The controller of claim 14 wherein the circuit comprises:
comparator circuitry that compares the control signal to a first, second, and third reference signals, the comparator circuitry respectively outputting first, second, and third comparator output signals; and
drive circuitry coupled to receive the first, second, and third comparator output signals, the drive circuitry outputting the drive signal responsive to the first, second, and third comparator output signals.
18. The controller of claim 14 wherein the drive signal is a pulsed drive signal coupled to control switching of the power switch.
19. The controller of claim 17 wherein the comparator circuitry further compares the control signal to a fourth reference signal and outputs a fourth comparator output signal to the drive circuitry, wherein when the control signal is less than the third threshold and greater than the second threshold, a pulse width modulation (PWM) dimming operation is implemented with respect to the output signal delivered to the load.
20. The controller of claim 16 wherein the comparator circuitry comprises first, second, and third comparators coupled to receive the first, second, and third reference signals, and output the first, second, and third comparator output signals, respectively.
21. The controller of claim 19 wherein the first, second, and third comparators are each voltage comparators.
22. The controller of claim 19 wherein the first, second, and third comparators are each current comparators.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of broadcasting packets through a network of switches, the method comprising:
receiving a packet to broadcast through the network of switches;
selecting a broadcast path from a plurality of generated broadcast paths;
creating a broadcast path tag associated with the selected broadcast path;
inserting the broadcast path tag into the packet;
determining port(s) by which to forward the packet;
transmitting the packet, with the broadcast path tag embedded therein, via the port(s) to next switch(es) in accordance with the selected broadcast path;
receiving the packet by a hop switch;
reading the broadcast path tag embedded therein;
determining port(s) by which to forward the packet; and
transmitting the packet, with the broadcast path tag embedded therein, via the port(s) to next switch(es) in accordance with the selected broadcast path.
2. The method of claim 1, wherein the port(s) are determined by looking up the broadcast path tag in a tag table.
3. The method of claim 1, further comprising:
receiving the packet by a destination switch;
reading the broadcast path tag embedded therein; and
determining that an end of a branch of the broadcast path has been reached.
4. The method of claim 1, wherein the packet is forwarded outside the network of switches by removing the broadcast path tag from the packet and broadcasting the packet (with the broadcast path tag removed) outside of the network of switches.
5. The method of claim 1, wherein the method comprises multipath broadcasting in that different broadcast paths are selected to broadcast packets depending on specific criteria.
6. The method of claim 1, wherein the broadcast path tag comprises a source switch identifier, a code indicating a broadcast, and a path identifier.
7. A method of broadcasting packets through a network of switches, the method comprising:
receiving a packet to broadcast through the network of switches;
selecting a broadcast path from a plurality of generated broadcast paths;
creating a broadcast path tag associated with the selected broadcast path;
inserting the broadcast path tag into the packet;
determining port(s) by which to forward the packet; and
transmitting the packet, with the broadcast path tag embedded therein, via the port(s) to next switch(es) in accordance with the selected broadcast path,
wherein the method comprises multipath broadcasting in that different broadcast paths are selected to broadcast packets depending on specific criteria, and
wherein the criteria relates to a type of the packet.
8. A method of broadcasting packets through a network of switches, the method comprising:
receiving a packet to broadcast through the network of switches;
selecting a broadcast path from a plurality of generated broadcast paths;
creating a broadcast path tag associated with the selected broadcast path;
inserting the broadcast path tag into the packet;
determining port(s) by which to forward the packet; and
transmitting the packet, with the broadcast path tag embedded therein, via the port(s) to next switch(es) in accordance with the selected broadcast path,
wherein the method comprises multipath broadcasting in that different broadcast paths are selected to broadcast packets depending on specific criteria, and
wherein the criteria relates to load balancing across the different broadcast paths.
9. A switching device configured to be a member of a switching mesh, the switching device comprising:
a plurality of ports;
a switch control device coupled to the plurality of ports,
wherein the switch control device is configured to provide multiple broadcast paths from a source switch through the switching mesh;
a layer 2 media access (MAC) table which includes broadcast path tags associated with the multiple broadcast paths; and
a tag table referenced by the broadcast path tags.
wherein the tag table comprises a broadcast flag.
10. The switching device of claim 9, wherein the switch control device comprises an application specific integrated circuit (ASIC).
11. The switching device of claim 9, wherein the switch control device comprises a central processing unit configured to execute sequences of instructions.
12. The switching device of claim 9, wherein the switching device holds full knowledge of the multiple broadcast paths.
13. The switching device of claim 9, wherein if the broadcast flag is set for an entry in the tag table, then the path tag of the entry is utilized to index into a broadcast port map filter.
14. The method of claim 9, wherein the broadcast paths comprise spanning trees, and wherein the method is performed by an owner switch at a root of the spanning tree.