IP Library Patent Application 13626013
Patent Application
App. No. 13/626,013

Dual-Port Memory and a Method Thereof

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Quick Facts
Patent No.
US None
App. No.
13/626,013
Abstract

A dual-port memory is provided. The dual-port memory includes a first single-port memory and a second single-port memory. The first single-port memory is configured to store data in an even address of the dual-port memory. The second single-port memory is configured to store data in an odd address of the dual-port memory. The dual-port memory simultaneously performs a read operation to read data from the odd address and a write operation to write data into the even address. The dual-port memory simultaneously performs a read operation to read data from the even address and a write operation to write data into the odd address.

Claims (45)

1 . A dual-port memory, comprising:

a first single-port memory configured to store data at an even address of the dual-port memory; and

a second single-port memory configured to store data at an odd address of the dual-port memory, wherein

the dual-port memory simultaneously performs a read operation to read data from the odd address and a write operation to write data into the even address, and

the dual-port memory simultaneously performs a read operation to read data from the even address and a write operation to write data into the odd address.

2 . The dual-port memory of claim 1 , further comprising:

a first pair of multiplexers comprising a first multiplexer and a second multiplexer and configured to provide a chip enable signal to at least one of the first single-port memory and the second single-port memory by selecting an external read operation enable signal and an external write operation enable signal,

wherein the first multiplexer is coupled to the first single-port memory, and the second multiplexer is coupled to the second single-port memory.

3 . The dual-port memory of claim 2 , further comprising:

a second pair of multiplexers comprising a third multiplexer and a fourth multiplexer and configured to provide a write enable signal to at least one of the first single-port memory and the second single-port memory by selecting the external write operation enable signal and a signal mask,

wherein the third multiplexer is coupled to the first single-port memory, and the fourth multiplexer is coupled to the second single-port memory.

4 . The dual-port memory of claim 3 , further comprising:

a third pair of multiplexers comprising a fifth multiplexer and a sixth multiplexer and configured to provide a read/write address to at least one of the first single-port memory and the second single-port memory based on an external read address and an external write address,

wherein the fifth multiplexer is coupled to the first single-port memory, and the sixth multiplexer is coupled to the second single-port memory.

5 . The dual-port memory of claim 4 , wherein the third pair of multiplexers provides a read address to at least one of the first single-port memory and the second single-port memory based on a quotient of the external read address divided by two; and

the third pair of multiplexers provides a write address to at least one of the first single-port memory and the second single-port memory based on a quotient of the external write address divided by two.

6 . The dual-port memory of claim 4 , wherein a pair of selection signals in each pair of said multiplexers are opposite to each other when the read operation and the write operation are performed simultaneously.

7 . The dual-port memory of claim 4 , wherein a selection signal of each multiplexer is determined by a parity of the external read address and the external write address.

8 . The dual-port memory of claim 7 , wherein the selection signal of each multiplexer is determined based on a least significant bit (LSB) of the external read address and a least significant bit (LSB) of the external write address.

9 . The dual-port memory of claim 4 , further comprising:

an output multiplexer configured to output data read from the first single-port memory or the second single-port memory.

10 . The dual-port memory of claim 9 , further comprising:

a flip-flop configured to provide a selection signal to the output multiplexer, wherein the selection signal is determined by a parity of the external read address and the external write address.

11 . A method, comprising:

storing data at an even address of a dual-port memory into a first single-port memory;

storing data at an odd address of said dual-port memory into a second single-port memory;

enabling the first single-port memory and the second single-port memory by a first pair of multiplexers;

providing a write enable signal to a selected single-port memory of the first single-port memory and the second single-port memory by a second pair of multiplexers to enable the selected single-port memory to perform a write operation; and

providing a write address to the selected single-port memory by a third pair of multiplexers to enable the selected single-port memory to write data into the write address.

12 . The method of claim 11 , further comprising:

providing a read address to the other single-port memory of the first single-port memory and the second single-port memory by the third pair of multiplexers to enable the other single-port memory to perform a read operation and read data from the read address.

13 . The method of claim 12 , wherein the first pair of multiplexers comprise a first multiplexer and a second multiplexer, and are configured to provide a chip enable signal to the first single-port memory and the second single-port memory by selecting an external read operation enable signal and an external write operation enable signal to enable the first single-port memory and the second single-port memory,

wherein the first multiplexer is coupled to the first single-port memory, and the second multiplexer is coupled to the second single-port memory.

14 . The method of claim 13 , wherein the second pair of multiplexers comprise a third multiplexer and a fourth multiplexer, and are configured to provide the write enable signal to the selected single-port memory by selecting the external write operation enable signal and a signal mask,

wherein the third multiplexer is coupled to the first single-port memory, and the fourth multiplexer is coupled to the second single-port memory.

15 . The method of claim 14 , wherein the third pair of multiplexers comprise a fifth multiplexer and a sixth multiplexer, and are configured to provide the write address to the selected single-port memory and provide the read address to the other single-port memory based on an external read address and an external write address.

16 . The method of claim 15 , wherein the third pair of multiplexers provide the read address to the other single-port memory based on a quotient of the external read address divided by two, and

the third pair of multiplexers provide the write address to the selected single-port memory based on a quotient of the external write address divided by two.

17 . The method of claim 15 , wherein a pair of selection signals in each pair of the multiplexers are opposite to each other when the read operation and the write operation are performed simultaneously.

18 . The method of claim 15 , wherein a selection signal of each multiplexer is determined by a parity of the external read address and the external write address.

19 . The method of claim 18 , wherein the selection signal of each multiplexer is determined based on a least significant bit (LSB) of the external read address and a least significant bit (LSB) of said external write address.

20 . The method of claim 15 , further comprising:

outputting data read from the other single-port memory by an output multiplexer.

21 . The method of claim 20 , further comprising:

providing a selection signal to the output multiplexer by a flip-flop, wherein the selection signal is determined by a parity of the external read address and the external write address.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 27, 2012
From: O2MICRO, INC.
To: MAISHI ELECTRONIC (SHANGHAI) LTD.
Reel/Frame 029353/0824 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 25, 2012
From: ZHANG, WEIHUA; YU, MEI
To: O2MICRO INC.
Reel/Frame 029018/0842 →