JP2002311060A - Waveform measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waveform measuring instrument capable of efficiently conducting analysis of a waveform pattern of data flowing in a serial bus including a flow direction of data between a master and a plurality of slaves. SOLUTION: The waveform measuring instrument for analyzing and displaying data flowing in the serial bus for connecting the master and the plurality of the slaves, includes a main screen part for displaying whole data to be analyzed, a zoom display part for enlarging and displaying a frame specified by a zoom specifying means from the data to be analyzed on the main screen with a set zoom magnification, and a part for displaying an analysis result as a list for displaying the analysis result as a list while interlocking with a positional change of the zoom specifying means and scrolling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a waveform measuring instrument, and more particularly to a waveform analysis display of data flowing through a serial bus.

[0002]

2. Description of the Related Art A serial bus interface is often used as a bus interface for connecting digital ICs mounted on a board, because the number of signal lines can be reduced as compared with a parallel bus interface.

One of such serial bus interfaces is an SPI (Serial Per Interface) proposed by Motorola.
ipheral Interface) bus. This SPI bus is
Clock SCK (Serial Clock) and data output SDO
(Serial Data Output) and data input SDI (Serial D
ata Input) and three other signal lines.
A signal line for a chip select signal CS (Chip Select) functioning as a slave identification signal for controlling the output of the slave is also provided.

FIG. 2 is a connection example diagram of a master M and slaves S1 to S3 by an SPI bus. The SPI bus controls transmission and reception of data between the master M and the plurality of slaves S1 to S3 by controlling the chip select signal CS.

The data output SDO pins of the slaves S1 to S3 become high impedance when the chip select signal CS is at H level, and output data when the chip select signal CS is at L level. Then, the master M sends the chip select signals C of the slaves S1 to S3 to communicate with.
S is selectively set to the L level to perform data communication with the selected slave.

[0006]

By the way, in the development and maintenance of such a device using the SPI bus, although the waveform of each signal line has been conventionally observed using, for example, an oscilloscope, Observing even the direction of data flow between the master and multiple slaves was not considered.

An object of the present invention is to solve such a problem, and an object of the present invention is to efficiently analyze a waveform pattern of data flowing through a serial bus, including a data flow direction between a master and a plurality of slaves. It is to provide a waveform measuring instrument.

[0008]

According to a first aspect of the present invention, there is provided a waveform measuring instrument for analyzing and displaying data flowing through a serial bus connecting a master and a plurality of slaves. A main screen section for displaying the entire data, an arbitrary frame to be zoom-displayed from the data to be analyzed on the main screen and a zoom specifying means for specifying a zoom magnification, and a frame specified by the zoom specifying means are set. Analysis result including a zoom display unit for enlarging and displaying at a zoom magnification ratio, frame numbers and data of a plurality of frames including a frame specified by the zoom specifying unit, and a slave identification signal unique to each slave transmitted from the master for each slave. Analysis result list display unit that displays a list while scrolling in conjunction with the position change of the zoom designation means, Characterized by a frame zoom designation means designates one of the analysis result list display section analysis results displayed list to be distinguished from other frame display.

According to a second aspect of the present invention, in the waveform measuring device of the first aspect, the serial bus is an SPI bus.

According to a third aspect of the present invention, in the waveform measuring device according to the first or second aspect, a frame to be enlarged and displayed on the zoom display section is specified from the analysis result list display section.

As a result, data flowing through the serial bus, particularly data flowing through the SPI bus, can be efficiently analyzed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a display example diagram showing an example of an embodiment of the present invention in which the SPI bus of FIG. 2 is an observation target. FIG.
The display screen includes three display units including a main screen unit 10, a zoom screen unit 20, and an analysis result list display unit 30, and an operation instruction unit 40.

The main screen unit 10 displays a waveform of the clock SCK, a waveform of the data input SDI of the master M, and a waveform of the chip select signal CS as a slave identification signal assigned to each of the three slaves S1 to S3. The entire waveforms of the three data to be analyzed are displayed.

On the main screen 10, a zoom box 11 functioning as a zoom designating means for designating an arbitrary frame to be zoom-displayed from the data to be analyzed and a zoom magnification is also displayed.

The zoom screen section 20 includes a zoom box 11
The waveform of the clock SCK, the waveform of the data input SDI of the master M, and the waveform of the chip select signal CS assigned to each of the three slaves S1 to S3 for the frame of the analysis target data designated by Is enlarged according to the zoom magnification rate set by the width of.

The analysis result list display section 30 displays a frame number “N” assigned to a plurality of frames including the frame designated by the zoom box 11 in the waveform measuring instrument in the arrangement order.
o. And data Dt1 and Dt2 input to the master M.
(Data Dt2 is not shown) and the master M
From each slave S1 transmitted from each of the slaves S1 to S3
Bit numbers B0 to B2 of the chip select signal CS unique to 1 to S3 (B0 = Bit0, B1 = Bit1, B2 =
Analysis results including Bit 2) are displayed in a list while scrolling in conjunction with a change in the position of the zoom box 11.

In the example of FIG. 1, eleven frames are displayed, and the analysis result in each frame can be read as digital data.

The frame box 31 provided in the analysis result list display section 30 corresponds to the frame specified by the zoom box 11 among the analysis results displayed on the analysis result list display section 30, and is different from other frames. It is displayed so that it can be identified.

The operation instruction section 40 of FIG. 1 is provided with five buttons 41 to 45.

The button 41 calls up a dialog box (not shown) for setting desired analysis conditions.

The button 42 instructs execution of analysis according to the set analysis conditions.

A button 43 switches to a data search screen by a pattern search (not shown).

The button 44 is for controlling the zoom box 11, and the position of the zoom box 11 on the main screen 10 and the width of the zoom box 11 can be adjusted and set arbitrarily.

The button 45 causes the analysis result list display section 3
The position of the frame box 31 provided at the position 0 is moved. In conjunction with the movement of the position of the frame box 31 on the analysis result list display unit 30 by the button 45, the zoom box 1 on the main screen 10 is moved.
The position of 1 also changes.

That is, the operator sets the target frame for zoom display on the zoom box 1 on the main screen 10.
1 can be specified by changing the position of the frame box 31 on the analysis result list display section 30.

In the connection of FIG. 2, a plurality of slaves S1
No data is sent to master M simultaneously from .about.S3. Therefore, when the master M is receiving data,
Which of the slaves S1 to S3 is transmitted from
It can be known from the level change of the chip select signal CS. That is, the chip select signal CS is at the H level in the normal state where no data is transmitted, but is at the L level during data transmission.

When the master M is receiving data, by checking the level of the chip select signal CS of each of the slaves S1 to S3 with an oscilloscope, it is possible to identify from which slave the data is transmitted.

For example, in FIG.
The chip select signals CS of the slaves S1 to S3 in FIG. 2 are input to each of t2. When the master M is receiving data, the chip select signal CS of any one of the slaves S1 to S3 should be at the L level,
At this time, any one of Bit0 to Bit2 in FIG. 1 should be at the L level. If the signal level of Bit0 is L, it means that the slave S1 is transmitting data.

In FIG. 1, as described above, by displaying these Bit0 to Bit2 on the analysis result list display section 30, it is possible to know which of the three slaves S1 to S3 is transmitting data. Like that.

In FIG. 1, the waveforms of the chip select signal CS on the main screen 10 and the zoom screen section 20 are not displayed, and those areas are assigned to the clock SCK and the data input SDI of the master M to enlarge them. You may make it display with high precision. In this case, the information of the chip select signal CS can be understood by looking at the analysis result of CS in the analysis result list display section 30.

The operator operates the chip select signal C unique to each of the slaves S1 to S3 on such a display screen.
Based on S, the slave that is performing data transmission with the master M can be accurately identified.

In the embodiment, the analysis result list display unit 3
The frame corresponding to the frame specified by the zoom box 11 among the analysis results displayed at 0 is displayed so as to be distinguishable from other frames by providing the frame box 31. However, the display color and display luminance of the frame are displayed. May be different.

Although the example in which the slave identification signal is a chip select signal has been described, any signal may be used as long as the signal can be identified substantially by a plurality of slaves individually.

In the above embodiment, the example of the SPI bus has been described. However, the present invention is not limited to the SPI bus. A similar effect can be obtained as long as it is configured to be identified.

[0035]

As described above, according to the present invention,
A waveform measuring instrument capable of efficiently analyzing the waveform pattern of data flowing through the serial bus, including the direction of data flow between the master and a plurality of slaves, can be realized, and is suitable for various developments and maintenance including the serial bus.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a display screen of an analysis result based on the present invention.

FIG. 2 is an explanatory diagram of connection between a master and a plurality of slaves via a serial bus.

[Explanation of symbols]

 Reference Signs List 10 Main screen part 20 Zoom screen part 30 Analysis result list display part 40 Operation instruction part

Claims (3)

[Claims] 1. A waveform measuring instrument for analyzing and displaying data flowing through a serial bus connecting a master and a plurality of slaves, comprising: a main screen for displaying the entire data to be analyzed; and data to be analyzed on the main screen. A zoom designation unit for designating an arbitrary frame to be zoom-displayed and a zoom magnification ratio, a zoom display unit for enlarging and displaying the frame designated by the zoom designation unit at the set zoom magnification ratio, and the zoom designation unit designating the zoom display unit. Analysis in which a list of frame numbers and data of a plurality of frames including frames and analysis results including a slave identification signal transmitted from the master for each slave to each slave are displayed in a scrolled manner in conjunction with a change in position of the zoom designation means. And a result list display section. Waveform measuring instrument, characterized in that beam designation means distinguishably displays a frame to specify the other frames. 2. The waveform measuring instrument according to claim 1, wherein the serial bus is an SPI bus. 3. The waveform measuring instrument according to claim 1, wherein a frame to be enlarged and displayed on the zoom display section is designated from the analysis result list display section.