MEMORY ACCESS CONTROLLER AND METHOD THEREOF

• US 20080034139A1
• Filed: 07/30/2007
• Published: 02/07/2008
• Est. Priority Date: 08/01/2006
• Status: Abandoned Application

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Han, Qi, Xiao, Yan
• Application Number:
  US11/829,956
• Publication Number:
  US 20080034139A1
• Time in Patent Office: Days
• US Class Current: 710/110
• CPC Class Codes: G06F 13/1605 based on arbitration arbitration in handling access to a common bus or bus system G06F13/36

Abstract

A memory access controller that improves SDRAM access performance with the enhanced AHB bus protocol includes at least one memory access master for issuing a memory access instruction including an HLEN signal that represents the burst length of the transmitting data; and a memory access controller for controlling the access to the memory on the basis of the HLEN signal generated by the memory access master.

Claims

1. A memory access control apparatus connected to a memory via a bus, comprising:

at least one memory access master connected to the bus for issuing a memory access instruction including a HLEN signal that represents the burst length of data to be transmitted on the bus; and

a memory access controller coupled to the at least one memory access master for controlling the access to the memory on the basis of the HLEN signal generated by the memory access master.

2. The memory access control apparatus of claim 1, further comprising a HLEN enable line for applying a HLEN enable signal to the memory access controller.

3. The memory access control apparatus of claim 2, wherein the memory access control apparatus supports an AHB system bus and the memory access master further generates a HBURST signal complying with the AHB system bus.

4. The memory access control apparatus of claim 3, wherein for a fixed burst length transfer, the HLEN is equal with HBURST length if the burst length transfer is unknown.

5. The memory access control apparatus of claim 3, wherein for an increment unfixed burst length transfer, the HBURST signal is used and the HLEN signal is ignored.

6. The memory access control apparatus of claim 1, wherein the memory access controller comprises:

at least one memory access slave for generating a memory access request on the basis of the memory access instruction issued by the corresponding memory access master and feeding the information of the memory access controller back to the corresponding memory access master;

at least one HLEN signal decoder for decoding the HLEN signal included in the memory access instruction issued by the corresponding memory access master;

an arbiter for receiving the memory access request generated by the memory access slave and sorting the received memory access requests to generate sequential access commands;

a command buffer for sequentially storing the access commands generated by the arbiter; and

a command controller for reading the access command stored in the command buffer and generating a memory access instruction to control the transmission of the data.

7. A memory access controller, comprising:

at least one memory access slave for receiving a memory access instruction issued by a corresponding memory access master, generating a memory access request and providing the information of the memory access controller back to the corresponding memory access master, wherein the memory access instruction issued by the corresponding memory access master includes a HLEN signal that represents the burst length of the transmitting data;

at least one HLEN signal decoder for decoding the HLEN signal included in the memory access instruction issued by the corresponding memory access master;

an arbiter for receiving the memory access request generated by the memory access slave and sorting the received memory access requests to generate sequential access commands;

a command buffer for sequentially storing the access commands generated by the arbiter; and

a command controller for reading the access command stored in the command buffer and generating a memory access instruction to control the transmission of the data.

8. The memory access controller of claim 7, further comprising a HLEN enable line for applying a HLEN enable signal to the memory access controller.

9. The memory access controller of claim 8, wherein the memory access controller supports an AHB system bus and the memory access master further generates a HBURST signal complying with the AHB system bus.

10. The memory access controller of claim 9, wherein for fixed burst length transfer, the HLEN is equal with HBURST length if the burst length transfer is unknown.

11. The memory access controller of claim 9, wherein for increment unfixed burst length transfer, the HBURST signal is used and the HLEN signal is ignored.

12. A memory access control method for controlling access to a memory, comprising the steps of:

issuing at least one memory access instruction including a HLEN signal that represents a burst length of data to be transmitted over a bus; and

controlling the access to the memory on the basis of the HLEN signal.

13. The memory access control method of claim 12, further comprising the step of issuing a HLEN enable signal, wherein memory access is dependent on the HLEN signal.

14. The memory access control method of claim 13, wherein the memory access control method supports an AHB system bus and further comprises the step of generating a HBURST signal complying with the AHB system bus.

15. The memory access control method of claim 14, wherein for fixed burst length transfer, the HLEN is equal with HBURST length if the burst length transfer is unknown.

16. The memory access control method of claim 14, wherein for increment unfixed burst length transfer, the HBURST signal is used and the HLEN signal is ignored.

17. The memory access control method of claim 12, wherein the controlling step comprises the steps of:

generating a memory access request on the basis of the memory access instruction;

decoding the HLEN signal included in the memory access instruction;

receiving the memory access request and sorting the received memory access requests to generate sequential access commands;

sequentially storing the access commands; and

reading the access command and generating a memory access instruction to control the transmission of the data.

18. A memory access control method comprising:

receiving a memory access instruction, the memory access instruction includes a HLEN signal that represents a burst length of data being transmitted;

generating a memory access request on the basis of the memory access instruction;

decoding the HLEN signal;

receiving the memory access request and sorting the received memory access requests to generate sequential access commands;

sequentially storing the access commands; and

reading the access command and generating a memory access instruction to control the transmission of the data.

19. The memory access control method of claim 18, further comprising the step of issuing a HLEN enable signal to allow the memory access to be dependent on the HLEN signal.

20. The memory access control method of claim 19, wherein the memory access control method supports an AHB system bus and further comprises the step of generating a HBURST signal complying with the AHB system bus.