Claims
- 1. A data processing device comprising:a program counter; and program counter trace stack means for holding a predetermined number of addresses defining a history of address discontinuities in operation of said program counter, the trace stack has entries pushable thereon and storage elements for extra bits for the entries, the data processing device further including an overflow signal producing element having an input and an output, a signal combining circuit having a first input connected to one of the storage elements and a second input and an output respectively connected to the output and input of the overflow signal producing element.
- 2. The data processing device of claim 1 further comprising a program counter stack.
- 3. The data processing device of claim 1 further comprising means for storing a state vector representing whether a particular address in said program counter trace stack means is a beginning or ending address of a discontinuity.
- 4. The data processing device of claim 1 wherein said program counter trace stack means includes means for recording how many entries have been pushed onto the stack.
- 5. The data processing device of claim 1 further comprising means connected to said program counter trace stack for producing a signal indicating when the stack is full.
- 6. The data processing device of claim 1 further comprising a program memory connected to said program counter, an instruction decoder connected to said program memory, and an electronic adding and multiplying circuit connected to said instruction decoder.
- 7. The data processing device of claim 1 wherein the address discontinuities include discontinuities resulting from external interrupts.
- 8. The data processing device of claim 1 further comprising an externally accessible serial scan circuit interconnected with said program counter trace stack.
- 9. The data processing device of claim 8, wherein said trace stack means is connected in series with said serial scan circuit to define therewith a serial scan path for permitting external access to the addresses stored in said trace stack means.
- 10. The data processing device of claim 9, wherein said trace stack control means includes means for generating a state vector representing whether a particular address in said trace stack means is a beginning or ending address of a discontinuity.
- 11. The data processing device of claim 10, including a shift register operatively associated with said trace stack means for storing said state vector, said shift register being loaded in said serial scan path for permitting external access to said state vector.
- 12. The data processing device of claim 11, wherein said shift register is arranged to permit serial shifting of said state vector out of said shift register along a signal path which is separate and distinct from said serial scan path.
- 13. The data processing device of claim 12, including means connected to said signal path for examining said state vector to determine when said trace stack means is full.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application Ser. No. 07/832,661, filed Feb. 4, 1992, now U.S. Pat. No. 6,032,268; which was a continuation of application Ser. No. 07/388,286, filed Jul. 31, 1989 now abandoned. This application is a continuation in part of the following applications, which are hereby incorporated herein by reference:
application Ser. No. 07/093,463, (TI-12698) filed Sep. 4, 1987, abandoned;
application Ser. No. 07/140,055, (TI-12541), filed Dec. 31, 1987 now U.S. Pat. No. 5,109,491;
application Ser. No. 07/140,192, (TI-12543), filed Dec. 31, 1987, now U.S. Pat. No. 5,101,498;
application Ser. No. 07/347,968, (TI-14083) filed May 4, 1989, now U.S. Pat. No. 5,829,054;
application Ser. No. 07/347,969, (TI-14147) filed May 4, 1989, now U.S. Pat. No. 5,724,248;
application Ser. No. 07/347,605, (TI-14079) filed May 4, 1989, now U.S. Pat. No. 5,586,275;
application Ser. No. 07/347,596, (TI-14080) filed May 4, 1989, now U.S. Pat. No. 5,072,418;
application Ser. No. 07/347,615, (TI-14081) filed May 4, 1989, now U.S. Pat. No. 5,142,677;
application Ser. No. 07/347,966, (TI-14082) filed May 4, 1989, now U.S. Pat. No. 5,155,812;
application Ser. No. 07/347,967, (TI-14145) filed May 4, 1989, now U.S. Pat. No. 5,617,574.
The following coassigned applications are also incorporated herein by reference.
application Ser. No. 07/386,936, (TI-14312) filed Jul. 28, 1989, now U.S. Pat. No. 5,237,672;
application Ser. No. 07/387,569, (TI-14315) filed Jul. 28, 1989, abandoned;
application Ser. No. 07/387,455, (TI-14316) filed Jul. 28, 1989, abandoned;
application Ser. No. 07/387,850, (TI-14320) filed Jul. 28, 1989, abandoned;
application Ser. No. 07/387,568, (TI-13495) filed Jul. 28, 1989, now U.S. Pat. No. 5,233,690;
application Ser. No. 06/948,337, (TI-11398), filed Dec. 31, 1986, abandoned; and
application Ser. No. 06/057,078, (TI-12033) filed Jun. 2, 1987, now U.S. Pat. No. 4,860,290.
This application is among and related to coassigned applications application Ser. No. 07/388,270, filed Jul. 31, 1989, abandoned; application Ser. No. 07/387,475, now U.S. Pat. No. 6,085,336; and application Ser. No. 07/388,275, now U.S. Pat. No. 5,329,471, all filed contemporaneously and hereby incorporated herein by reference.
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Continuations (1)
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07/388286 |
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07/832661 |
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Continuation in Parts (10)
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07/347968 |
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07/388286 |
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07/347969 |
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07/347968 |
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07/347605 |
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07/347969 |
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07/347596 |
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07/347605 |
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07/347615 |
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07/347596 |
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07/347966 |
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07/347615 |
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07/347967 |
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07/347966 |
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07/140055 |
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07/347967 |
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07/140192 |
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07/140055 |
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07/093463 |
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07/140192 |
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