Segmented on-chip memory and requester arbitration

• US 20060047910A1
• Filed: 04/15/2005
• Published: 03/02/2006
• Est. Priority Date: 08/31/2004
• Status: Active Grant

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Baer, Matthias, Tischer, Falk, Goetting, Oliver, Schlegel, Peer
• Granted Patent: US 7,461,191 B2
• Time in Patent Office: Days
• US Class Current: 711/115
• CPC Class Codes: G06F 13/1605 based on arbitration arbitration in handling access to a common bus or bus system G06F13/36
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y10S 370/913 Wireless or radio

Abstract

A memory access technique is provided that may be used in WLAN (Wireless Local Area Network) communication devices. An on-chip memory has multiple memory circuits forming individually addressable memory segments. An arbitration unit arbitrates between multiple requesters, each requesting access to the on-chip memory. The requesters are on-chip circuits and/or external devices. The arbitration unit determines a memory circuit to be accessed for each request that is received from a requester. The determination may be based on a software configurable arbitration scheme. The memory segments may form a bank of single-port SRAM (Static Random Access Memory) devices.

Claims

1. A WLAN (Wireless Local Area Network) communication device adapted to be 802.11 compliant, the WLAN communication device comprising:

an on-chip memory adapted to buffer data frames received and/or to be transmitted by the WLAN communication device, said on-chip memory having separate, individually addressable memory segments;

at least one interface interfacing to at least one external device; and

an arbitration unit connected to said on-chip memory and said at least one interface to control access of multiple requesters to the separate, individually addressable memory segments, at least one of said multiple requesters being said at least one external device.

2. The WLAN communication device of claim 1, being 802.11b and/or 802.11i compliant.

3. The WLAN communication device of claim 1, wherein said at least one external device comprises an SD (Secure Digital) media type device.

4. The WLAN communication device of claim 1, wherein said at least one external device comprises a CF (Compact Flash) media type device.

5. The WLAN communication device of claim 1, wherein each separate, individually addressable memory segment comprises an individual SRAM (Static Random Access Memory) device.

6. The WLAN communication device of claim 5, wherein each individual SRAM device is a single-port SRAM device.

7. The WLAN communication device of claim 1, wherein at least two of said separate, individually addressable memory segments are single-port RAM (Random Access Memory) devices.

8. The WLAN communication device of claim 1, wherein said separate, individually addressable memory segments are physical memory segments.

9. The WLAN communication device of claim 8, wherein each of said separate, individually addressable memory segments is addressable by the same physical address space.

10. The WLAN communication device of claim 9, wherein each of said separate, individually addressable memory segments is addressable by a different logical address space.

11. The WLAN communication device of claim 10, wherein the multiple different logical address spaces are arranged to form a continuous logical address space so that the physical structure of said on-chip memory comprising said memory segments is hidden to any requester requesting access to the memory.

12. The WLAN communication device of claim 1, wherein at least one of said memory segments is reserved to form a buffer for received data frames.

13. The WLAN communication device of claim 1, wherein said arbitration unit comprises a memory controller adapted to select, for each individual requester being served, a respective memory segment.

14. The WLAN communication device of claim 13, wherein said memory controller comprises a configuration register storing segment information accessable to select the memory segments.

15. The WLAN communication device of claim 14, wherein said configuration register is configurable by software.

16. The WLAN communication device of claim 13, wherein said memory controller is adapted to perform address translation to translate logical addresses to physical addresses, said memory controller being connected to said on-chip memory to provide said physical addresses to said on-chip memory.

17. The WLAN communication device of claim 1, wherein said arbitration unit comprises a set of address mapping units adapted to perform address translation to translate logical addresses to physical addresses.

18. The WLAN communication device of claim 17, wherein said arbitration unit further comprises a set of arbitration subunits each adapted to control access of said multiple requesters to an individual one of said memory segments.

19. The WLAN communication device of claim 18, wherein each of said arbitration subunits is connected to all of said address mapping units to receive memory read and/or write requests.

20. The WLAN communication device of claim 18, wherein each of said arbitration subunits is connected to all of said address mapping units to cause any address mapping unit that performs address translation for a requester which is selected to get memory access to send a grant signal to the respective requester.

21. The WLAN communication device of claim 20, wherein the arbitration subunits and address mapping units are adapted to de-assert a grant signal if a corresponding memory read and/or write request is dropped.

22. The WLAN communication device of claim 17, wherein said address mapping units are adapted to perform said address translation dependent on the number of memory segments in said on-chip memory.

23. The WLAN communication device of claim 1, further comprising an address decoder connected to said at least one interface, said address decoder being adapted to decode addresses and perform data transfer to and/or from said on-chip memory.

24. The WLAN communication device of claim 1, further comprising a multiplexer/demultiplexer unit to multiplex and/or demultiplex data received from and/or sent to said multiple requesters accessing said on-chip memory.

25. The WLAN communication device of claim 1, wherein at least one of said multiple requesters is a security module of said WLAN communication device.

26. The WLAN communication device of claim 25, wherein said security module is adapted to apply the AES (Advanced Encryption Standard) data encryption scheme.

27. The WLAN communication device of claim 25, wherein said security module is adapted to apply the TKIP (Temporal Key Integrity Protocol) data encryption scheme.

28. The WLAN communication device of claim 1, wherein at least one of said multiple requesters is a MAC (Medium Access Control) unit of said WLAN communication device.

29. The WLAN communication device of claim 1, wherein the data frames buffered by said on-chip memory are provided by at least one of said multiple requesters, either by software or by hardware.

30. The WLAN communication device of claim 1, wherein said arbitration unit is adapted to operate according to an arbitration scheme configurable by software.

31. The WLAN communication device of claim 30, wherein said arbitration scheme is configurable to adapt arbitration to throughput requirements relating to data traffic originating from at least some of said multiple requesters.

32. The WLAN communication device of claim 31, wherein said at least some of said multiple requesters comprise at least one external device.

33. The WLAN communication device of claim 31, wherein said at least some of said multiple requesters comprise a security module of the WLAN communication device.

34. The WLAN communication device of claim 30, wherein said arbitration scheme is configurable to adapt to a varying number of requesters.

35. The WLAN communication device of claim 30, wherein at least one of said memory segments is preferentially assigned to only one of said multiple requesters.

36. The WLAN communication device of claim 1, wherein said arbitration unit is adapted to operate according to a round robin arbitration scheme.

37. The WLAN communication device of claim 1, wherein said arbitration unit is adapted to operate according to a priority based arbitration scheme where each of said multiple requesters is assigned a priority.

38. The WLAN communication device of claim 37, wherein requesters having assigned higher priorities are preferentially served.

39. The WLAN communication device of claim 37, wherein said priority based arbitration scheme is configurable by software.

40. The WLAN communication device of claim 37, wherein said priorities are assignable by software.

41. The WLAN communication device of claim 37, wherein said priority based arbitration scheme is configurable with respect to the number of priority levels available.

42. The WLAN communication device of claim 37, wherein said arbitration unit is further adapted to operate according to a round robin arbitration scheme.

43. An integrated circuit chip comprising:

an on-chip memory having multiple memory circuits forming individually addressable memory segments; and

an arbitration circuit adapted to arbitrate between multiple requesters each requesting access to said on-chip memory, said requesters being on-chip circuits and/or external devices coupled to said integrated circuit chip, said arbitration circuit adapted to determine, for each request received from a requester, a memory circuit to be accessed, wherein said determination is based on a software configurable arbitration scheme.

44. The integrated circuit chip of claim 43, wherein each memory circuit comprises an SRAM (Static Random Access Memory) circuit.

45. The integrated circuit chip of claim 44, wherein each SRAM device is a single-port SRAM circuit.

46. The integrated circuit chip of claim 43, wherein at least two of said memory circuits are single-port RAM (Random Access Memory) circuits.

47. The integrated circuit chip of claim 43, wherein each of said separate, individually addressable memory segments is addressable by the same physical address space.

48. The integrated circuit chip of claim 47, wherein each of said memory circuits is addressable by a different logical address space.

49. The integrated circuit chip of claim 48, wherein the multiple different logical address spaces are arranged to form a continuous logical address space so that the physical structure of said on-chip memory comprising said memory circuits is hidden to any requester requesting access to the memory.

50. The integrated circuit chip of claim 43, wherein said arbitration circuit comprises a memory control circuit adapted to select, for each individual requester being served, a respective memory circuit.

51. The integrated circuit chip of claim 50, wherein said memory control circuit comprises a configuration register storing segment information accessable to select the memory circuits.

52. The integrated circuit chip of claim 50, wherein said memory control circuit is adapted to perform address translation to translate logical addresses to physical addresses, said memory control circuit being connected to said on-chip memory to provide said physical addresses to said on-chip memory.

53. The integrated circuit chip of claim 43, wherein said arbitration circuit comprises a set of address mapping circuit adapted to perform address translation to translate logical addresses to physical addresses.

54. The integrated circuit chip of claim 53, wherein said arbitration circuit further comprises a set of arbitration sub-circuits each adapted to control access of said multiple requesters to an individual one of said memory circuits.

55. The integrated circuit chip of claim 54, wherein each of said arbitration sub-circuits is connected to all of said address mapping units to receive memory read and/or write requests.

56. The integrated circuit chip of claim 54, wherein each of said arbitration sub-circuits is connected to all of said address mapping units to cause any address mapping circuits that performs address translation for a requester which is selected to get memory access to send a grant signal to the respective requester.

57. The integrated circuit chip of claim 56, wherein the arbitration sub-circuits and address mapping circuits are adapted to de-assert a grant signal if a corresponding memory read and/or write request is dropped.

58. The integrated circuit chip of claim 53, wherein said address mapping circuits are adapted to perform said address translation dependent on the number of memory circuits in said on-chip memory.

59. The integrated circuit chip of claim 43, further comprising an address decoder connected to said at least one interface, said address decoder being adapted to decode addresses and perform data transfer to and/or from said on-chip memory.

60. The integrated circuit chip of claim 43, further comprising a multiplexer/demultiplexer circuit to multiplex and/or demultiplex data received from and/or sent to said multiple requesters accessing said on-chip memory.

61. The integrated circuit chip of claim 43, wherein said arbitration scheme is configurable by software to adapt arbitration to throughput requirements relating to data traffic originating from at least some of said multiple requesters.

62. The integrated circuit chip of claim 43, wherein at least one of said requesters is a security module.

63. The integrated circuit chip of claim 43, wherein at least one of said requesters is a MAC (Medium Access Control) circuit.

64. The integrated circuit chip of claim 43, wherein said arbitration scheme is configurable by software to adapt to a varying number of requesters.

65. The integrated circuit chip of claim 43, wherein at least one of said memory circuits is preferentially assigned to only one of said multiple requesters.

66. The integrated circuit chip of claim 43, wherein said arbitration scheme is a round robin arbitration scheme.

67. The integrated circuit chip of claim 43, wherein said arbitration scheme is a priority based arbitration scheme where each of said multiple requesters is assigned a priority.

68. The integrated circuit chip of claim 67, wherein requesters having assigned higher priorities are preferentially served.

69. The integrated circuit chip of claim 67, wherein said priorities are assignable by software.

70. The integrated circuit chip of claim 67, wherein said priority based arbitration scheme is configurable with respect to the number of priority levels available.

71. The integrated circuit chip of claim 67, wherein said arbitration unit is further adapted to operate according to a round robin arbitration scheme.

72. A memory device comprising:

an on-chip bank of single-port SRAM (Static Random Access Memory) devices,

wherein said on-chip bank of single-port SRAM devices has a data port and an address port, said address port coupleable to an arbiter for having access of multiple requesters to said on-chip bank controlled by selecting at least one of said single-port SRAM devices and physically address memory cells in the selected single-port SRAM device.

73. A method of controlling access to an on-chip memory, comprising:

receiving requests from multiple requesters to read data from and/or write data to said on-chip memory;

determining which one of the received requests is to be served next;

for the determined request, determining which one of multiple separate, individually addressable memory segments of said on-chip memory is to be used; and

addressing a memory cell in the determined memory segment to read or write data to or from said memory cell in compliance with the determined request.

74. A computer readable storage medium storing instructions that, when executed by a processor, cause said processor to configure an arbiter to arbitrate between multiple requesters each requesting access to an on-chip memory having multiple separate, individually addressable memory segments by determining, for each request received from a requester, a memory segment to be accessed and addressing a memory cell in the determined memory segment to read or write data to or from said memory cell in compliance with the determined request.