Semiconductor device including a plurality of circuits and a bus connecting the circuits to one another, and method of operating the semiconductor device
A semiconductor device includes a plurality of circuits, a general bus configured to be connected to each of the plurality of circuits and to provide a general channel among the plurality of circuits, and a designated bus configured to be connected to a subgroup of circuits from among the plurality of circuits and to provide a designated channel among the subgroup of circuits.
1. A semiconductor device comprising:
a plurality of circuits;
a general bus that is directly connected to each of the plurality of circuits and provides a general channel among the plurality of circuits; and
a designated bus that is directly connected to a subgroup of circuits among the plurality of circuits and provides a designated channel among the subgroup of circuits, wherein
the subgroup of circuits contains fewer than all of the plurality of circuits,
the subgroup of circuits is prohibited from performing a communication through the general bus while the subgroup of circuits performs a communication through the designated bus, and
a communication conveyed through the general bus is not conveyed through the designated bus.
2. The semiconductor device of claim 1 , wherein the subgroup of circuits is prohibited from performing a communication through the designated bus while the subgroup of circuits performs a communication through the general bus.
3. The semiconductor device of claim 1 , wherein the subgroup of circuits handles general work having lower priority through the general bus and handles work having higher priority through the designated bus.
4. The semiconductor device of claim 1 , wherein:
at least one circuit of the subgroup of circuits receives a request from an external device, and
the subgroup of circuits exclusively selects: (a) the general bus to perform a communication depending on a first characteristic of the request and (b) the designated bus to perform the communication depending on a second characteristic of the request.
5. The semiconductor device of claim 1 , wherein:
at least one circuit of the subgroup of circuits receives a request from an external device, and
the subgroup of circuits selects one of the general bus and the designated bus to perform a communication depending on a depth of a queue allocated to process the request.
6. The semiconductor device of claim 1 , wherein the plurality of circuits comprises:
a host interface that communicates with an external host device;
a manager circuit that communicates with a nonvolatile memory device;
a buffer control circuit that communicates with a random access memory; and
a processor that controls the host interface, the manager circuit, and the buffer control circuit.
7. The semiconductor device of claim 6 , wherein the subgroup of circuits comprises the host interface and the manager circuit.
8. The semiconductor device of claim 7 , wherein the host interface controls connections to the general bus and the designated bus such that a connection to the designated bus is activated when: (a) a priority of a request received from the external host device is high, (b) a depth of a queue allocated by the external host device is smaller than a reference value, or (c) a retransmission request due to a time-out is received from the external host device.
9. The semiconductor device of claim 6 , wherein the host interface, the manager circuit, the buffer control circuit, the processor, the nonvolatile memory device, the random access memory, the designated bus, and the general bus form a solid state drive (SSD).
10. The semiconductor device of claim 1 , wherein:
the designated bus directly connects a first circuit and a second circuit from among the subgroup of circuits, and
a communication conveyed through the general bus is not conveyed through the designated bus.
11. The semiconductor device of claim 10 , wherein:
the designated bus directly connects a third circuit and a fourth circuit from among the subgroup of circuits, and
a communication conveyed through the general bus is not conveyed through the designated bus.
12. The semiconductor device of claim 1 , wherein:
the designated bus connects first through third circuits from among the subgroup of circuits to one another, and
a communication conveyed through the general bus is not conveyed through the designated bus.
13. The semiconductor device of claim 1 , wherein the plurality of circuits comprises:
a modem that communicates with an external device;
a user input device that receives a signal from a user;
a user output device that outputs a signal to the user;
a random access memory that temporarily stores data;
a storage device that stores data long term; and
a processor that controls the modem, the user input device, the user output device, the random access memory, and the storage device.
14. A semiconductor device comprising:
a plurality of circuits;
a general bus connected to each of the plurality of circuits; and
a designated bus connected to a first circuit and a second circuit from among the plurality of circuits, wherein
the first circuit determines a priority of a request with respect to the second circuit, accesses the second circuit through the designated bus upon a determination that the priority of the request is high, and accesses the second circuit through the general bus upon a determination that the priority of the request is low.
15. The semiconductor device of claim 14 , wherein:
the designated bus is further connected to a third circuit among the plurality of circuits, and
the third circuit determines a priority of another request with respect to the second circuit, accesses the second circuit through the designated bus upon a determination that the priority of the other request is high, and accesses the second circuit through the general bus upon a determination that the other request is low.
16. The semiconductor device of claim 14 , further comprising:
a second designated bus connected to a third circuit and a fourth circuit among the plurality of circuits, wherein
the third circuit determines a priority of another request with respect to the fourth circuit, accesses the fourth circuit through the designated bus upon a determination that the priority of the other request is high, and accesses the fourth circuit through the general bus upon a determination that the other request is low.
17. A storage device comprising:
a nonvolatile memory device; and
a memory controller that controls operations in the nonvolatile memory device responsive to an external request, wherein:
the memory controller comprises a plurality of circuits, a general bus that is connected to each of the plurality of circuits, and a designated bus that is connected to a first circuit and a second circuit from among the plurality of circuits,
the first circuit accesses the second circuit selectively through the designated bus and the general bus according to a priority of the external request, and
the second circuit provides communication between the first circuit and the nonvolatile memory device.
18. The storage device of claim 17 , wherein the first circuit accesses the second circuit through the designated bus upon a determination that the priority is high and accesses the second circuit through the general bus upon a determination that the priority is low.
19. The storage device of claim 17 , wherein:
the memory controller further comprises a second designated bus connected to a third circuit and a fourth circuit from among the plurality of circuits, and
the third circuit accesses the fourth circuit selectively through the second designated bus and the general bus according to a priority of another external request.