Non-intrusive debug port interface

• US 20100011130A1
• Filed: 07/08/2008
• Published: 01/14/2010
• Est. Priority Date: 07/08/2008
• Status: Active Grant

• Current Assignee: Nuvoton Technology Corporation (Winbond Electronics Corporation)
• Original Assignee: Nuvoton Technology Corporation (Winbond Electronics Corporation)
• Inventors: Tasher, Nir, Flachs, Victor, Shamis, Leonid, Mayer, Shani, Peled, Nimrod
• Granted Patent: US 8,006,004 B2
• Time in Patent Office: Days
• US Class Current: 710/6
• CPC Class Codes: G06F 11/3656 using a specific debug interface

Abstract

A processor having a core configured to control a keyboard and a plurality of pins connected to the core, configured to transfer signals from the processor to the keyboard. A controller is configured to transfer signals from one or more registers through at least one of the pins, intermittently with signals transferred to the keyboard.

Claims

1. A processor, comprising:

a core configured to control a keyboard;

a plurality of pins connected to the core, configured to transfer signals from the processor to the keyboard;

one or more registers; and

a controller configured to transfer signals from the one or more registers through at least one of the pins, intermittently with signals transferred to the keyboard.

2. A processor according to claim 1, wherein the core comprises an embedded controller configured to control systems of a notebook computer.

3. A processor according to claim 1, wherein the one or more registers comprise at least two registers.

4. A processor according to claim 1, wherein the one or more registers comprise debug code registers configured to store debug codes of the processor.

5. A processor according to claim 1, wherein the one or more registers comprise debug code registers configured to store debug codes of a different processor, than the processor including the registers.

6. A processor according to claim 1, wherein the controller is configured to transfer content from the one or more registers through the at least one of the pins each time there is a change in signals directed to the keyboard transmitted through the at least one pins.

7. A processor according to claim 1, wherein the controller is configured to initiate transfer of content from the one or more registers through the at least one of the pins each time there is a change in a value of the one or more registers.

8. A processor according to claim 7, wherein the controller is configured to delay transfer of content from the one or more registers through the at least one of the pins when the core is reading signals from the keyboard.

9. A processor according to claim 1, wherein the controller is configured to abort transmission of content from the one or more registers through the at least one of the pins, in response to one or more occurrences in the processor.

10. A processor according to claim 9, wherein the controller is configured to abort transmission of content from the one or more registers through the at least one of the pins, in response to a request to read input from the keyboard.

11. A processor according to claim 9, wherein the controller is configured to abort transmission of content from the one or more registers through the at least one of the pins, in response to a change in the content of the one or more registers.

12. A processor according to claim 1, wherein the processor has a normal state in which the controller is inactive and a debug display mode in which the controller is active, and wherein the core is configured with firmware which is not changed in the switching between the normal state and the debug display mode.

13. A processor according to claim 1, wherein the controller is configured to operate properly without cooperation from firmware of the core.

14. A processor according to claim 1, wherein the controller is configured to delay reading of input from the keyboard until sufficient time has passed from transferring signals from the one or more registers through the one or more pins.

15. A processor according to claim 14, wherein the controller is configured to delay reading of input from the keyboard by stalling a bus of the processor.

16. A processor according to claim 1, wherein the controller is configured to provide a strobe signal along with each transfer of signals from the one or more registers.

17. A processor, comprising:

at least one multi-purpose output pin;

a first unit configured to transfer signals through the multi-purpose output pin;

a second unit configured to transfer signals through the multi-purpose output pin; and

a controller configured to stall the operation of the first unit, responsive to a determination that a transmission from the second unit through the multi-purpose output pin may interfere with correct operation of the first unit.

18. A processor according to claim 17, wherein the controller is configured to ensure that output from the first unit is provided without interruption through the multi-purpose output pin for at least a predetermined time before the first unit reads input from a device external to the processor.

19. A processor according to claim 17, wherein the controller is configured to abort transfer of signals from the second unit responsive to at least one specific occurrence within the processor.

20. A processor according to claim 17, wherein the first unit comprises a keyboard controller.

21. A processor according to claim 17, wherein the second unit comprises a debug code provider.

22. A processor, comprising:

at least one multi-purpose output pin;

a first unit configured to transfer signals through the multi-purpose output pin;

a second unit configured to transfer signals through the multi-purpose output pin; and

a controller configured to initiate transfer of signals from the second unit through the multi-purpose output pin whenever there is a change in the signals provided by the first unit on the multi-purpose output pin and the second unit is not already transferring signals on the multi-purpose output pin.

23. A processor according to claim 22, wherein the first unit comprises a keyboard controller.

24. A processor according to claim 22, wherein the second unit comprises a debug code provider.

25. A processor according to claim 22, wherein the second unit provides signals which change at an order of magnitude faster than the signals provided by the first unit.

26. A processor according to claim 22, wherein the second unit provides a strobe signal with the signals which change at an order of magnitude faster than the signals provided by the first unit.

27. A method of outputting information from a processor, comprising:

storing information in one or more registers within a processor;

providing keyboard scan signals via a specific pin of a processor; and

transmitting the information stored in the one or more registers, via the specific pin of the processor.

28. A method according to claim 27, wherein storing the information comprises storing debug codes.

29. A method according to claim 27, wherein providing keyboard scan signals via the specific pin comprises providing the scan signals less than 10% of the processor operation time.

30. A method according to claim 27, wherein transmitting the information comprises initiating transmission of the information each time the keyboard scan signal begins or ends, unless the state of the processor requires delay of the transmission.

31. A method according to claim 27, wherein transmitting the information comprises transmitting at times selected independent of timing of a keyboard scan process providing the keyboard scan signals.

32. A method according to claim 27, wherein transmitting the information comprises transmitting at times selected independent of whether keyboard scan signals are being provided via the specific pin.

33. A method according to claim 27, comprising stalling a keyboard read process of the processor responsive to identification of an attempt to read a state of the keyboard within a minimal settling time from a transmission of the information.