In-circuit emulator and pod synchronized boot

• US 8,160,864 B1
• Filed: 11/01/2001
• Issued: 04/17/2012
• Est. Priority Date: 10/26/2000
• Status: Expired due to Fees

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Nemecek, Craig, Roe, Steve
• Primary Examiner(s): Craig, Dwin M
• Application Number:
  US10/001,478
• Time in Patent Office: 3,820 Days
• Field of Search: 703/28, 716/4, 716/16, 716/106, 716/107, 716/108, 716/136, 714/11
• US Class Current: 703/28
• CPC Class Codes: G06F 11/3656 using a specific debug interface

Abstract

A synchronized boot process for an In-Circuit Emulator system. A real microcontroller is operated in lock-step synchronization with a virtual microcontroller to permit In-Circuit Emulation that allows debugging of the real microcontroller without interfering with its real time operation. The synchronized boot is accomplished by running boot code in the real microcontroller while the virtual microcontroller runs dummy code with the same timing as the boot code. Registers and memory contents are then copied from the real microcontroller to the virtual microcontroller to complete initialization and enter a state of readiness for lock-step operation.

Claims

1. A boot method for synchronizing a real microcontroller and a virtual microcontroller of an In-Circuit Emulation system in lock-step, comprising:

in the real microcontroller, executing a set of boot code to carry out initialization;

in the virtual microcontroller, executing a set of timing code to enable a lock-step synchronization with the real microcontroller, wherein the set of timing code is a dummy code timed to take the same number of clock cycles as the real microcontroller uses to execute the set of boot code, wherein the set of timing code is functionally different from the set of boot code, and wherein the set of boot code is stored within the real microcontroller and the set of boot code is inaccessible to the virtual microcontroller;

simultaneously halting both the real microcontroller and the virtual microcontroller; and

restarting the real microcontroller and the virtual microcontroller to execute instructions in lock-stepped synchronization.

2. The method according to claim 1, further comprising copying register contents from the real microcontroller to corresponding registers in the virtual microcontroller after completion of the simultaneous halting.

3. The method according to claim 1, wherein after the executing of the boot code, the real microcontroller branches to an assembly instruction line 0;

and wherein after the executing the timing code, the virtual microcontroller branches to the assembly instruction line 0.

4. The method according to claim 1, wherein prior to the executing of the boot code, and prior to the executing the timing code, a break is set at an assembly instruction line 0.

5. The method according to claim 1, wherein the boot code comprises protected initialization code that is protected from the In-Circuit Emulation system.

6. The method according to claim 1, further comprising:

prior to the executing of the boot code, and prior to the executing the timing code, setting a break at an assembly instruction line 0,

wherein after the executing of the boot code the real microcontroller branches to the assembly instruction line 0; and

wherein after the executing the timing code, the virtual microcontroller branches to the assembly instruction line 0.

7. The method according to claim 1, further comprising:

prior to the executing of the boot code, and prior to the executing the timing code, setting a break at an assembly instruction line 0;

wherein after the executing of the boot code, the real microcontroller branches to the assembly instruction line 0; and

wherein after the executing the timing code, the virtual microcontroller branches to the assembly instruction line 0;

copying register contents from the real microcontroller to corresponding registers in the virtual microcontroller; and

copying memory contents from the real microcontroller to corresponding memory in the virtual microcontroller,

wherein after the executing of the boot code, the real microcontroller branches to the assembly instruction line 0; and

wherein after the executing the timing code, the virtual microcontroller branches to the assembly instruction line 0.

8. The method according to claim 7, further comprising removing the break at the assembly line 0 after the copying the register contents and the copying the memory contents.

9. The method according to claim 1, wherein the set of boot code comprises proprietary information, wherein the proprietary information comprises serial numbers, passwords, and algorithms.

10. The method according to claim 1, wherein at least one portion of the boot code is inaccessible to the virtual microcontroller by being stored internally in the real microcontroller.

11. A boot method for synchronizing a real microcontroller and a virtual microcontroller of an In-Circuit Emulation system in lock-step, comprising:

resetting the real microcontroller and the virtual microcontroller to a halt state;

setting a break at an assembly instruction line 0;

in the real microcontroller, executing a set of boot code to carry out initialization;

in the virtual microcontroller, executing a set of timing code to enable a lock-step synchronization with the real microcontroller, wherein the set of timing code is a dummy code timed to take the same number of clock cycles as the real microcontroller uses to execute the set of boot code, wherein the set of timing code is functionally different from the set of boot code, and wherein the set of boot code is stored within the real microcontroller and the set of boot code is inaccessible to the virtual microcontroller;

simultaneously halting both the real microcontroller and the virtual microcontroller by branching to the assembly instruction line 0;

copying register contents from the real microcontroller to corresponding registers in the virtual microcontroller;

copying memory contents from the real microcontroller to corresponding memory in the virtual microcontroller; and

removing the break at the assembly line 0 after the copying the register-contents and the copying the memory contents.

12. A boot method for synchronizing a tested device and a virtual processor of an In-Circuit Emulation system in lock-step, comprising:

in the tested device, executing a set of boot code to carry out initialization;

in the virtual processor, executing a set of timing code to enable a lock-step synchronization with the tested device, wherein the timing code is a dummy code timed to take the same number of clock cycles as the tested device uses to execute the set of boot code, wherein at least one portion of the set of timing code is different from the set of boot code, and wherein the set of boot code is stored within the tested device and the set of boot code is inaccessible to the virtual processor;

simultaneously halting both the tested device and the virtual processor; and

restarting the tested device and the virtual microprocessor to execute instructions in lock-stepped synchronization.

13. The method according to claim 12, further comprising copying memory contents from memory coupled to the tested device to corresponding memory coupled to the virtual processor.

14. The method according to claim 12, wherein after the executing of the boot code, the tested device branches to an assembly instruction line 0;

and wherein after the executing the timing code, the virtual processor branches to the assembly instruction line 0.

15. The method according to claim 12, wherein prior to the executing of the boot code, and prior to the executing the timing code, a break is set at an assembly instruction line 0.

16. The method according to claim 12, wherein the boot code comprises protected initialization code that is not accessible to the in-Circuit Emulation system.

17. The method according to claim 12, further comprising:

prior to the executing of the boot code, and prior to the executing the timing code, setting a break at an assembly instruction line 0,

wherein after the executing of the boot code, the tested device branches to the assembly instruction line 0; and

wherein after the executing the timing code, the virtual processor branches to the assembly instruction line 0.

18. The method according to claim 12, further comprising:

prior to the executing of the boot code, and prior to the executing the timing code, setting a break at an assembly instruction line 0,

wherein after the executing of the boot code, the tested device branches to the assembly instruction line 0; and

wherein after the executing the timing code,

the virtual processor branches to the assembly instruction line 0;

copying register contents from the tested device to corresponding registers in the virtual processor; and

copying memory contents from the tested device to corresponding memory in the virtual processor,

wherein after the executing of the boot code, the tested device branches to the assembly instruction line 0; and

wherein after the executing the timing code, the virtual processor branches to the assembly instruction line 0.

19. The method according to claim 18, further comprising removing the break at the assembly instruction line 0 after the copying the register contents and the copying the memory contents.

20. The method according to claim 12, wherein the virtual processor is implemented in a field programmable gate array.