Trace buffer data management for emulation systems

Patent metadata

Field	Value
Publication number	US-12306732-B2
Application number	US-202217903925-A
Country	US
Kind code	B2
Filing date	Sep 6, 2022
Priority date	Sep 7, 2021
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

An emulation system traverses trace buffers to read data captured from a design under test (DUT). The emulation system receives a request to read at least a portion of DUT data. The emulation system reads a header of the latest sample of the DUT data, where header of each sample of the DUT data includes one or more pointers to a previously stored sample. The samples of the DUT data are partitioned into frames and sectors. The emulation system can identify samples of the DUT data using the pointers in the header of the samples and compare time stamps of the samples against a specified time stamp in the received request. After identifying a sample having the specified time stamp, the emulation system may read the sample for output to the user (e.g., reconstructing a waveform using the sample).

First claim

What is claimed is:

1. A system comprising:
a memory storing instructions; and
a processor, coupled with the memory and to execute the instructions, the instructions when executed cause the processor to:
receive a request for a read of at least a portion of DUT data, the request including a specified time stamp, wherein the DUT data is partitioned by a plurality of frames and wherein each of the plurality of frames comprises a plurality of sectors that further partition the DUT data;
read a header of a latest sample of the DUT data, the header having a previous frame header address;
compare, for a first plurality of samples identified using the previous frame header address, the specified time stamp with a time stamp of each of the first plurality of samples until a compared time stamp of a sample of the first plurality of samples is earlier than the specified time stamp, a header of the sample of the first plurality of samples having a previous sector header address;
compare, for a second plurality of samples identified using the previous sector header address, the specified time stamp with a time stamp of each of the second plurality of samples until a compared time stamp of a sample of the second plurality of samples is earlier than the specified time stamp, a header of the sample of the second plurality of samples having a previous sample header address;
compare, for a third plurality of samples identified using the previous sample header address, the specified time stamp with a time stamp of each of the third plurality of samples until a compared time stamp of a sample of the third plurality of samples is equivalent to the specified time stamp; and
read the portion of the DUT data from the sample of the third plurality of samples.

2. The system of claim 1 , wherein the latest sample of the DUT data is partitioned by a first frame, and wherein the previous frame header address corresponds to a first particular sample of the DUT data partitioned by a second frame different from the first frame.

3. The system of claim 2 , wherein the first particular sample of the DUT data is partitioned by a first sector, and wherein the previous sector header address corresponds to a second particular sample of the DUT data partitioned by a second sector different from the first sector.

4. The system of claim 1 , wherein the instructions, when executed by the processor, further cause the processor to:
identify the first plurality of samples by traversing a plurality of addresses corresponding to the first plurality of samples starting from the previous frame header address.

5. The system of claim 1 , wherein the instructions, when executed by the processor, further cause the processor to:
identify the second plurality of samples by traversing a plurality of addresses corresponding to the second plurality of samples starting from the previous sector header address.

6. The system of claim 1 , wherein the DUT data includes multiple samples, and wherein each sample of the DUT data comprises a corresponding header and one or more corresponding data packets, where each corresponding header includes a previous frame header address, a previous sector header address, and a previous sample header address.

7. The system of claim 1 , wherein each frame of the plurality of frames includes a determined number of sectors.

8. The system of claim 1 , wherein the instructions, when executed by the processor, further cause the processor to:
reconstruct a waveform using the read portion of the DUT data from the sample of the third plurality of samples.

9. A non-transitory computer readable medium comprising stored instructions, which when executed by a processor, cause the processor to:
receive a request for a read of at least a portion of DUT data, wherein the request includes a requested time stamp or a requested sample count, wherein data packets of the DUT data are stored in one or more partitions of a memory, wherein the DUT data is partitioned by a plurality of frames and wherein each of the plurality of frames comprises a plurality of sectors that further partition the DUT data, and wherein a header associated with a data packet indicates a corresponding partition used to store the data packet;
read a first header associated with a first data packet of a latest sample of the DUT data, the first header including an identifier of a partition associated with a previous sample of the DUT data;
identify, using the partition, a second header associated with a second data packet of the previous sample, wherein the second header includes a time stamp of the previous sample and a sample count of the previous sample;
compare one of the requested time stamp and the time stamp of the previous sample or the requested sample count with the sample count of the previous sample; and
read at least a data packet corresponding to the previous sample.

10. The non-transitory computer readable medium of claim 9 , wherein the latest sample of the DUT data is partitioned by a first frame, and wherein the previous sample of the DUT data is partitioned by a second frame different from the first frame.

11. The non-transitory computer readable medium of claim 9 , wherein the latest sample of the DUT data is partitioned by a first sector, and wherein the previous sample of the DUT data is partitioned by a second sector different from the first sector.

12. The non-transitory computer readable medium of claim 9 , wherein each frame of the plurality of frames includes a determined number of sectors.

13. A non-transitory computer readable medium comprising stored instructions, which when executed by a processor, cause the processor to:
receive a determined number of clock cycle intervals to sample internal state signals;
receive DUT data comprising the internal state signals and primary input signals;
sample the primary input signals on each clock cycle and the internal state signals on every determined number of clock cycles;
create, on each clock cycle, a header for a current sample of the DUT data, the header comprising a time stamp of the current sample, a sample count of the current sample, a last sample pointer, a last sector pointer, and a last frame pointer;
store, with each clock cycle, the header of the current sample of the DUT data with the time stamp; and
store the samples of internal state signals at each interval corresponding to the determined number of clock cycle intervals.

14. The non-transitory computer readable medium of claim 13 , wherein the stored instructions, when executed by the processor, further cause the processor to:
store a portion of the DUT data in a memory; and
align the stored portion of the DUT data with a memory data word size.

15. The non-transitory computer readable medium of claim 14 , wherein the stored instructions, when executed by the processor, further cause the processor to:
pad the portion of the DUT data stored in response to a data or a header size being smaller than the memory data word size.

16. The non-transitory computer readable medium of claim 13 , wherein the DUT data is partitioned by a plurality of frames and wherein each of the plurality of frames comprises a plurality of sectors that further partition the DUT data.

17. The non-transitory computer readable medium of claim 16 , wherein a first sample of the DUT data is partitioned by a first frame, and wherein one of the last frame pointers points to a second sample of the DUT data partitioned by a second frame different from the first frame.

18. The non-transitory computer readab

Assignees

• Synopsys Inc

Inventors

• Liang Chia-Wei
• Wang Wenxin
• Chen Meng-Tse
• Ono Goichiro
• Zhao Zhe
• Song Yang
• Sui Yu
• Xu Yuchen

Classifications

• G06F11/2289

  by configuration test · CPC title

• G06F11/273 Primary

  Tester hardware, i.e. output processing circuits {(G06F11/263 takes precedence)} · CPC title

• G06F11/261 Primary

  by simulating additional hardware, e.g. fault simulation · CPC title