Memory controller useable in a data processing system
View Patent ↗One embodiment relates to a memory controller using an independent memory controller bus in order to transfer data between two or more memories. One embodiment of a data processing system includes a system bus, a system bus master coupled to the system bus, a first memory controller for controlling a first memory, a second memory controller for controlling a second memory, and a memory controller bus operating independent of the system bus to transfer data between the first memory controller and the second memory controller. The memory controller bus may include a data bus and read, write, and acknowledge signals. In one embodiment, the first memory is a block accessible memory such as a NAND Flash memory and the second memory is a random access memory (RAM) such as an SDRAM. The second memory may include arbitration logic for arbitrating between the system bus master and the first memory controller.
1. A data processing system, comprising:
a system bus;
a system bus master, coupled to the system bus;
a first memory controller for controlling a first memory;
a second memory controller for controlling a second memory; and
a memory controller bus operating independent of the system bus, said memory controller bus being coupled to the first memory controller and to the second memory controller, said memory controller bus transferring data between the first memory controller and the second memory controller, wherein:
the second memory controller comprises arbitration logic for arbitrating between the system bus master and the first memory controller for access to the second memory;
when the data is transferred from the first memory controller to the second memory controller, the data is received by the first memory controller from the storage locations within the first memory prior to transferring the data to the second memory controller, and
when the data is transferred from the second memory controller to the first memory controller, the data is received by the second memory controller from storage locations within the second memory prior to transferring the data to the first memory controller.
2. A data processing system as in claim 1 , wherein the first memory is of a first memory type and the second memory is of a second memory type, and wherein the first memory type is different than the second memory type.
3. A data processing system as in claim 2 , wherein the first memory type comprises block accessible memory.
4. A data processing system as in claim 3 , wherein the first memory type comprises NAND Flash memory.
5. A data processing system as in claim 2 , wherein the second memory type comprises random accessible memory.
6. A data processing system as in claim 5 , wherein the second memory type comprises synchronous dynamic random access memory.
7. A data processing system as in claim 1 , wherein the second memory controller comprises an address counter for storing a starting address.
8. A data processing system as in claim 1 , wherein the first memory controller comprises a counter for counting a number of data portions transferred between the first memory and the second memory.
9. A data processing system as in claim 1 , wherein the memory controller bus comprises:
a plurality of data signals;
a read signal;
a write signal; and
an acknowledge signal.
10. A data processing system as in claim 1 , further comprising a third memory coupled to the system bus.
11. A data processing system as in claim 1 , wherein the data processing system is formed on a single integrated circuit.
12. A data processing system as in claim 1 , wherein the system bus master comprises a processor.
13. A data processing system as in claim 1 , wherein the system bus master comprises direct memory access (DMA) circuitry.
14. The data processing system of claim 1 , wherein:
when the data is transferred from the first memory controller to the second memory controller, the data is provided by the second memory controller to the second memory for storage in the second memory after transferring the data to the second memory controller, and
when the data is transferred from the second memory controller to the first memory controller, the data is provided by the first memory controller to the first memory for storage in the first memory after transferring the data to the first memory controller.
15. A data processing system, comprising:
a system bus;
a system bus master, coupled to the system bus;
a first memory controller, coupled to the system bus, for controlling a first memory;
a second memory controller, coupled to the system bus, for controlling a second memory;
arbitration logic, coupled to the second memory controller, said arbitration logic arbitrating between the system bus master and the first memory controller for access to the second memory; and
a memory controller bus operating independent of the system bus, said memory controller bus being coupled to the first memory controller and to the second memory controller, said memory controller bus transferring data between the first memory controller and the second memory controller.
16. A data processing system as in claim 15 , further comprising:
direct memory access (DMA) circuitry coupled to the system bus; and
a processor coupled to the system bus.
17. A data processing system as in claim 15 , wherein the first memory comprises block accessible memory.
18. A data processing system as in claim 15 , wherein the second memory comprises random accessible memory.
19. A data processing system, comprising:
a system bus;
a processor, coupled to the system bus;
direct memory access (DMA) circuitry coupled to the system bus;
system bus arbitration logic, coupled to the system bus, said system bus arbitration logic performing arbitration on the system bus;
a first memory controller for controlling a first memory;
a second memory controller for controlling a second memory;
a memory controller bus operating independent of the system bus, said memory controller bus being coupled to the first memory controller and to the second memory controller, said memory controller bus transferring data between the first memory and second memory by way of the first memory controller and the second memory controller; and
memory controller bus arbitration logic, coupled to the second memory controller, said arbitration logic performing arbitration between the system bus master and the first memory controller for access to the second memory.