Memory access without internal microprocessor intervention

• US 8,510,481 B2
• Filed: 01/03/2007
• Issued: 08/13/2013
• Est. Priority Date: 01/03/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Wilson, Thomas James, Hori, Yutaka
• Primary Examiner(s): Tsai, Henry
• Assistant Examiner(s): Shyu, Jing-Yih
• Application Number:
  US11/650,118
• Publication Number:
  US 20080162835A1
• Time in Patent Office: 2,414 Days
• Field of Search: None
• US Class Current: 710/22
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184

Abstract

A method and system for accessing a computer system memory without processor intervention is disclosed. In one embodiment, the method includes initiating a predetermined communication protocol between a first device and a second device, the first device including a first processor, a first memory and a first communication interface, the second device including a second processor, a second memory and a second communication interface. The predetermined communication protocol enables an access operation to be performed on the first or second memory without intervention by the first or second processor. In one embodiment, the predetermined communication protocol utilizes a plurality of predefined packet types which are identified by a packet header decoder.

Claims

1. A computer system, comprising:

a sensor panel;

a first device configured to receive and process sense signals from the sensor panel, the first device including a first processor, a first memory and a first communication interface; and

a second device, external to the first device, including a second processor, a second memory and a second communication interface, wherein the first and second devices communicate via the first and second communication interfaces implementing a predetermined communication protocol that enables an access operation to be performed on the first memory without intervention by the first processor;

wherein the access operation comprises storing a boot program from the second memory to the first memory; and

wherein the computer system further comprises;

an attention (ATN) line connecting the first communication interface and the second communication interface; and

a power manager module configured to initiate the access operation by generating a power manager boot request signal and transmitting the power manager boot request signal to the first communication interface,

wherein the power manager boot request signal causes a signal on the ATN line to be set to a predetermined state.

2. The computer system of claim 1, wherein the predetermined communication protocol comprises a packet-based communication protocol that includes a plurality of packet types each having a predefined header format.

3. The computer system of claim 2 wherein the first communication interface comprises:

a packet header decoder for identifying a packet type corresponding to a packet transmitted between the first and second communication interfaces; and

a logic device for executing instructions corresponding to the packet type without intervention by the first processor.

4. The computer system of claim 1 wherein the first communication interface comprises a first serial peripheral interface and the second communication interface comprises a second serial peripheral interface.

5. The computer system of claim 1, wherein the first communication interface further comprises a bus master interface configured to support execution of the access operation and wherein the access operation comprises the second device reading data stored in the first memory.

6. The computer system of claim 1, wherein the first communication interface further comprises a bus master interface configured to support execution of the access operation and wherein the access operation comprises the second device writing data to the first memory.

7. The computer system of claim 1, wherein the first communication interface further comprises a bus master interface configured to support execution of the access operation and wherein the access operation comprises a read-modify-write operation.

8. The computer system of claim 1 wherein the access operation comprises storing processed sense signals into the second memory.

9. The computer system of claim 8 wherein the second device comprises a host device, the second processor comprises a host processor and the second memory comprises a host memory of the system, wherein the host processor receives and further processes the processed sense signals from the first device and executes system functions based on the processed sense signals.

10. The computer system of claim 1 wherein the system is embodied in a mobile telephone.

11. The computer system of claim 1 wherein the system is embodied in a digital audio player.

12. The computer system of claim 1, wherein the first communication interface further comprises a bus master interface configured to support execution of the access operation.

13. The computer system of claim 1, wherein the second communication interface receives the ATN signal and transmits frames containing size information including the number of frames to be transmitted to the first communication interface.

14. The computer system of claim 13, wherein the first communication interface is configured to receive the frames containing size information, decode the size information, and retrieve the boot program from the second memory and store the boot program in the first memory without intervention by the first processor.

15. The computer system of claim 14, wherein the first communication interface generates no operation commands to the first communication interface to retrieve the boot program from the second memory and save the boot program into first memory.

16. The computer system of claim 6, wherein the second communication interface is configured to initiate the access operation by sending a memory write request command to the first communication interface, the memory write request command including a memory write address in the first memory and write data.

17. The computer system of claim 16, further comprising:

a receive first-in-first-out (RX FIFO) storage device configured to store the write data;

a packet header decoder configured to decode the memory write request command; and

a micro-sequencer configured to execute instructions for the memory write request command.

18. The computer system of claim 17, wherein the bus master interface is configured to retrieve the write data from the RX FIFO storage device, store the write data in a data register within the bus master interface, and load the write data to the memory write address in the first memory.

19. The computer system of claim 7, wherein the second communication interface is configured to initiate the access operation by sending a read-modify-write command packet to the first communication interface, the read-modify-write command packet including a read/write address in the first memory and write data.

20. The computer system of claim 19, further comprising:

a receive first-in-first-out (RX FIFO) storage device configured to store the write data;

a packet header decoder configured to decode the read-modify-write command packet; and

a micro-sequencer configured to execute instructions for the read-modify-write command packet and provide a read command to the bus master interface.

21. The computer system of claim 20, wherein the bus master interface is configured to receive the read command, retrieve data stored at the read/write address in the first memory, and store the retrieved data in a read register within the bus master interface.

22. The computer system of claim 21, wherein the data stored in the read register is updated with the write data stored in the RX FIFO.

23. The computer system of claim 22, wherein the micro-sequencer is configured to transmit a write request to the bus master interface.

24. The computer system of claim 23, wherein the bus master interface is configured to receive the write request and load the updated data in the read register to the read/write address in the first memory.

45. The computer system of claim 14, wherein the bus master interface is configured to receive a read command, retrieve the data stored in the first memory, and store the data in a transmit first-in-first-out (TX FIFO) storage device.

46. The computer system of claim 45, wherein the second communication interface is configured to extract the data from the TX FIFO storage device.

25. A computer system, comprising:

a first device configured to receive and process signals, the first device including a first processor, a first memory and a first communication interface; and

a second device, external to the first device, including a second processor, a second memory and a second communication interface, wherein the first and second devices communicate via the first and second communication interfaces implementing a predetermined communication protocol that enables an access operation to be performed on the first memory without intervention by the first processor;

wherein the first communication interface further comprises a bus master interface configured to support execution of the access operation and wherein the access operation comprises at least one of a read operation, a write operation or a read-modify-write operation;

wherein the second communication interface is configured to initiate the access operation; and

wherein the computer system further comprises;

a packet header decoder configured to decode the access operation; and

a micro-sequencer configured to execute instructions for the decoded access operation and provide commands to the bus master interface.

26. A computer system, comprising:

a first device including a first processor, a first memory and a first communication interface;

a second device, external to the first device, including a second processor, a second memory and a second communication interface, wherein the first and second devices communicate via the first and second communication interfaces implementing a predetermined packet-based communication protocol that utilizes a plurality of packet types each having a predefined header format;

a packet header decoder for identifying a packet type corresponding to a packet transmitted between the first and second communication interfaces; and

a logic device contained within the first communication interface configured to be responsive to the packet type and execute an access operation to be performed on the first memory without intervention by the first processor;

wherein the access operation comprises storing a boot program from the second memory to the first memory; and

wherein the access operation further comprises a read-modify-write operation performed on data stored in the first memory.

27. The computer system of claim 26 wherein the first communication interface comprises a first serial peripheral interface and the second communication interface comprises a second serial peripheral interface.

28. The computer system of claim 26 wherein the access operation comprises the second device reading data stored in the first memory.

29. The computer system of claim 26 wherein the access operation comprises the second device writing data to the first memory.

30. The computer system of claim 26 wherein the logic device comprises a micro-sequencer configured to execute micro-instructions based on the packet type.

31. The computer system of claim 26 wherein the system is embodied in a mobile telephone.

32. The computer system of claim 26 wherein the system is embodied in a digital audio player.

33. A method of accessing a computer system memory, comprising:

initiating a predetermined communication protocol between a first device and a second device, the first device including a first processor, a first memory and a first communication interface, the second device including a second processor, a second memory and a second communication interface, and

using the predetermined communication protocol, enabling an access operation to be performed on the first memory without intervention by the first or second processor;

wherein using the predetermined communication protocol includes identifying a packet header for identifying a packet type corresponding to a packet transmitted between the first and second communication interfaces; and

in response to the identified packet type executing an access operation to be performed on the first memory without intervention by the first processor;

wherein the access operation comprises storing a boot program from the second memory to the first memory; and

wherein the access operation further comprises a read-modify-write operation performed on data stored in the first memory.

34. The method of claim 33 wherein the access operation comprises the second device reading data stored in the first memory.

35. The method of claim 33 wherein the access operation comprises the second device writing data to the first memory.

36. The method of claim 33 wherein the access operation comprises storing processed sense signals received by the first device from a touch surface device into the second memory.

37. A computer system, comprising:

means for initiating a predetermined communication protocol between a first device and a second device, the first device including a first processor, a first memory and a first communication interface, the second device including a second processor, a second memory and a second communication interface, and

wherein the predetermined communication protocol utilizes a plurality of packet types each having a predefined header format and enables an access operation to be performed on the first or second memory without intervention by the first processor;

wherein using the predetermined communication protocol includes means for identifying a packet header for identifying a packet type corresponding to a packet transmitted between the first and second communication interfaces; and

in response to the identified packet type means for executing an access operation to be performed on the first memory without intervention by the first processor;

wherein the access operation comprises storing a boot program from the second memory to the first memory; and

wherein the access operation further corn rises a read-modify-write operation performed on data stored in the first memory.

38. The system of claim 37 further comprising:

means for identifying a packet type corresponding to a packet transmitted between the first and second communication interfaces; and

means for executing instructions corresponding to the packet type without intervention by the first processor.

39. The system of claim 37 wherein the access operation comprises the second device reading data stored in the first memory.

40. The system of claim 37 wherein the access operation comprises the second device writing data to the first memory.

41. The system of claim 37 wherein the access operation comprises storing processed sense signals received by the first device from a touch surface device into the second memory.

42. A mobile telephone, comprising:

a sensor panel;

a first device configured to receive and process sense signals from the sensor panel, the first device including a first processor, a first memory and a first communication interface; and

a second device, external to the first device, including a second processor, a second memory and a second communication interface, wherein the first and second devices communicate via the first and second communication interfaces implementing a predetermined communication protocol that enables an access operation to be performed on the first memory without intervention by the first processor;

the first communication interface further comprising;

a packet header decoder for identifying a packet type corresponding to a packet transmitted between the first and second communication interfaces; and

a logic device configured to be responsive to the packet type and execute an access operation to be performed on the first memory without intervention by the first processor;

wherein the access operation comprises storing a boot program from the second memory to the first memory; and

wherein the access operation further comprises a read-modify-write operation performed on data stored in the first memory.

43. A digital audio player, comprising:

a sensor panel;

a first device configured to receive and process sense signals from the sensor panel, the first device including a first processor, a first memory and a first communication interface; and

a second device, external to the first device, including a second processor, a second memory and a second communication interface, wherein the first and second devices communicate via the first and second communication interfaces implementing a predetermined communication protocol that enables an access operation to be performed on the first memory without intervention by the first processor;

the first communication interface further comprising;

a packet header decoder for identifying a packet type corresponding to a packet transmitted between the first and second communication interfaces; and

a logic device configured to be responsive to the packet type and execute an access operation to be performed on the first memory without intervention by the first processor;

wherein the access operation comprises storing a boot program from the second memory to the first memory; and

wherein the access operation further comprises a read-modify-write operation performed on data stored in the first memory.

44. A computer system, comprising:

a sensor panel;

a first device configured to receive and process sense signals from the sensor panel, the first device including a first processor, a first memory and a first communication interface; and

a second device, external to the first device, including a second processor, a second memory and a second communication interface, wherein the first and second devices communicate via the first and second communication interfaces implementing a predetermined communication protocol that enables an access operation to be performed on the first memory without intervention by the first processor;

wherein the second communication interface is configured to initiate the access operation by sending a memory read request command to the first communication interface

wherein the first communication interface further comprises a bus master interface configured to support execution of the access operation and wherein the access operation comprises the second device reading data stored in the first memory;

a packet header decoder configured to decode the access operation; and

a micro-sequencer configured to execute instructions for the decoded access operation and provide commands to the bus master interface.