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Method and System for Starting and Stopping of Writing of Trace Array

IP.com Disclosure Number: IPCOM000206879D
Publication Date: 2011-May-12
Document File: 4 page(s) / 168K

Publishing Venue

The IP.com Prior Art Database

Abstract

A method and system for starting and stopping of writing of trace array is disclosed.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 53% of the total text.

Page 01 of 4

Method and System for Starting and Stopping of Writing of Trace Array

A method and system for starting and stopping of the writing of trace array is disclosed. Trace Array is an instrumentation logic used to recorded on-chip signal activities on a cycle-by-cycle basis. Figure 1 shows a trace array with 2048 entries deep and 1664 bits wide. The Trace Write Controller controls the starting and stopping of writing of the trace array. The Trace Array Read Controller shown in dotted rectangle is used for reading out of contents of the traced information. Trace array may be read broadside but it can also be read in groups of 32 bits.

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Figure 1

Trace Write Controller includes a Trigger Signal Generator (TSG) shown in Figure 2. TSG receives event stimulus and generates a one cycle trigger

signal pulse. There are

two TSG's. The first TSG is used for controlling when the trace

                                        _write signal of Figure 1 is to be turned ON and the second TSG is used for controlling when the trace

_write

_signal

_type code is first loaded in a

Device Control Register (DCR). DCR are groups of read-only and/or read-write 32-bit registers for storing configuration and operational parameters for proper chip

_

signal is to be turned OFF. There are four kinds of events from which a trigger

pulse is generated. They are as follows:

Trigger on an error


Trigger on external signal Trigger on a software event Trigger on a pattern match

Now referring to Figure 2, a user defined 2-bit trigger

1


Page 02 of 4

operations. This code will determine which event type is to be selected for the trace operation. No event happens until the trigger

_enable is loaded in a DCR bit. A pulse

_trigger will manifest the first occurrence of the selected event. This pulse will

_signal to either pulse immediately or pulse after a number of cycles.

_cycles initially loaded in one of the

DCR latch. A decrementer will decrease the 12-bit initial value by one every cycle until it reaches zero. Hence, maximum number of delay cycles is 4096 which is twice the array depth.

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Figure 2

_write pulse is set by the "SG for Sta...