JPS58113863A - Logic analyzer - Google Patents

Abstract

PURPOSE:To enable the effective utilization of retrieval even in a timing display mode, by counting the total number of phenomena retrieved from stored data, and by displaying the relation between the position of a cursor and the total number of phenomena. CONSTITUTION:A data component and a grid component of input logic signals from a probe 10 are stored sequentially in memory circuits 14 and 18 respectively via a comparator and grid detector 12. When a display instruction is inputted from a keyboard 30, the content of memory of the memory circuit 14 and 18, a display mode and a display region information are stored in RAM28, the content of RAM28 is read out repeatedly by a display control circuit 32, and logic waveforms are displayed in CRT34. When a retrieval mode is selected by the keyboard 30, CPU24 compares search words with data informations, counts the total number of the search words, and further the number of search words contained before the address of the position of a cursor is stored, and makes CRT34 display these numbers.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a logic analyzer having a search function.

With the development of microprocessor and converter technology, logic technology has become common in various electronic devices. (1) Measurement for developing, adjusting, and repairing electronic devices using logic technology. Instruments include oscilloscopes, logic probes, and logic analyzers.

In particular, logic analyzers can randomly access and memo multiple channels of input logic signals (data)! J
Since the data stored in this storage means is displayed on a display means such as a cathode ray tube (CRT), logic technology is used because the bird can measure data before the signal is generated. Ideal for measuring instruments of electronic equipment. Logic analyzers have two display modes: one is a timing display mode that displays logic signals as signal waveforms, and the other is a timing display mode that displays stored data in binary, octal, or hexadecimal format. This is a state display mode in which letters (including numbers) are displayed as words such as.

In particular, in the state display mode, due to the relationship between the display area and the size of the characters, it is not possible to display all the data stored in the storage means (-), and only the data in the selected address range of the storage means is displayed.

Conventional logic analyzers have various functions, one of which is a search function (search mode). This function is especially used in the state display mode, and searches the data stored in the storage means by searching and
It searches for words. The searched word was displayed on the first line along with the address of the storage means, and a predetermined number of words following that address were displayed on the second and subsequent lines as a state table. However, as mentioned above, in the state display mode, it is not possible to display all the data stored in the storage means, so the total number of search words included in all the data, as well as this total number and the search function cannot be used in the display means mode. It was inconvenient to measure the timing of multiple channels of logic signals in a given word□
・.

Another function of conventional logic analyzers is the detection of glitches (narrow whisker-like pulse signals that adversely affect the operation of logic circuits). Glitches can be detected by increasing the clock frequency when storing human logic signals in the storage means, but there is a limit to the maximum frequency of the clock due to the characteristics of the storage means, so it is generally configured with logic circuits such as latch circuits. The glitch was detected by a glitch detector. The detected glitch was displayed as a 1-bit "1" pulse in the timing display mode (the glitch display may be luminance modulated). However, the glitch contained in all the data stored in the storage means The measurement was inconvenient because the total number and the relationship between this total number and the glitch displayed on the display means were unknown.

It was not possible to determine whether the displayed data was complete data without glitches.

According to the logic analyzer of the present invention, search words and phenomena such as glitches are entered by manual means, and the processing means counts the total number of phenomena to be searched from data stored in the storage means. Furthermore, this processing means determines the relationship between the cursor position controlled by the cursor control means and the total number of phenomena, and displays it on the display means.

Accordingly, one of the objects of the present invention is to provide a logic analyzer which improves the drawbacks of the prior art mentioned above.

Another object of the present invention is to provide a logic analyzer that can obtain the relationship between the total number of predetermined phenomena contained in stored input logic signals and the position of a cursor on a display means.

Still another object of the present invention is to determine the total number of predetermined words included in a stored human input logic signal and a display means. The objective is to provide a logic analyzer that can obtain the relationship between

It is an object of the present invention to provide a logic analyzer that can obtain the relationship between the total number of predetermined phenomena contained in input logic signals stored in the timing display mode and the state display mode and the cursor position (5).

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

The probe 10 has eight tips and detects eight channels of input logic signals from the circuit under test.

The eight channels of logic signals from the probe 10 are fed to a comparator and glitch detector 12, which adjusts the level of the input logic signal to the logic level appropriate for each block in FIG. A circuit 16 is supplied with a circuit 16 consisting of a glitch detection circuit), a counter, etc. A glitch detector in block 12 detects glitches from the input logic signal and
The signal is supplied to the glitch memory circuit 18, which is stored in a master circuit. Blocks 14, 16, 18 are connected (6) to path 20 (including data, address and control buses). The start/stop control circuit 22 starts the storage operation of the storage circuits 14 and 18 in response to a command from the bus 20, and stops this storage operation in response to an output from the trigger circuit 16. The central processing unit (CPU) 24 is, for example, a commercially available Z80A type microprocessor, and operates as a processing means. The read-only memory (ROM) 26 is the CPU
The RAM 28 is a memory circuit for firmware that stores the data processing contents of the CPU 24.
It operates as a temporary storage circuit and also includes display areas RA and M. It is used for inputting phenomena to be searched in the ROM 26 and R mode, and for other collaterals and inputs, and is connected to the bus 20. Therefore keyboard 30
operates as input means and cursor control means. The display □ control circuit 32 is connected to the bus 20 and generates a luminance signal, horizontal and vertical scanning signals based on the data in the display RAM area of the RAM 28, and outputs a rask scanning type C which is a display means.
Display RT34t1 data. The clock pulse generator 36 supplies clock pulses with a frequency corresponding to the command (1) from the bus 20 to the blocks 1, 4, 16, 18, etc. The clock frequency of the blocks 24, 26, 28, 30, etc. It is fixed at 4 MHz (when the CPU 24 is Z80A).

When storing a human logic waveform, first use the keyboard 30
Set the clock frequency, trigger word, and trigger delay clock number. These setting data are stored in a first area of the RAM 28 via the bus 20 and the CPU 24 (RAM 28). Next, a write start command from the keyboard 30 is sent to the start/stop control circuit 22 via the bus 20 and the CPU 24. Once supplied,
This circuit 22 puts the data-intensive storage circuit 14 and the glitch storage circuit 18 into write mode and starts a write operation. As mentioned above, the data component and glitch component of the human logic signal from probe 10 are sequentially stored via block 12 at different addresses in storage circuits 14 and 18, respectively. Note that the addresses of the memory circuits 14 and ]8 are designated by address signals from an address generator (not shown). Note that the addresses of storage circuits 14 and 18 correspond to each other on each clock pulse.

As described above, after the word recognizer in the trigger circuit 16 detects a tri-word from the data component of the input logic signal and the counter counts a set number of clocks, an output signal is generated. In response to this output signal, start/stop control circuit 22 halts the write operation of storage circuits 14 and 18. Therefore, storage of the logic signal under test into the storage circuits 14 and 18 is completed.

When a display command is input from the keyboard 30, the CPU 2
4 is based on the firmware of ROM28, and memory circuit 1
4 and 18 are transferred to the second and third areas of the RAM 28, respectively. Furthermore, the keyboard 30 is used to select the display mode (timing or state display mode) and the display area (9) (which part of the memorized logic signal under test should be displayed and
It is stored via PU24. Hereinafter, it is assumed that the selected display mode is the timing display mode. Based on the firmware in the ROM 26, the CPU 24 converts the data information in the second area of the RAM 28 corresponding to the selected display area into logic waveform font information, and converts the glitch information in the third area into attribute information. A ROM that stores font and attribute information in the RAM 28 and the shapes of characters and symbols, a shift register that converts the paranol output of this ROM into a serial signal (2, converts it into a Z-axis (luminance) signal, and vertically outputs it to the CRT 34) The logic waveform is displayed as shown in Figure 3. In Figure 3, "AO" to "A7" displayed on the left side (10) indicate the channel number of each logic signal, and correspond to each tip of the probe 10. do.

These channel numbers are displayed in a manner similar to a series of logic waveforms based on the firmware in ROM 26. Furthermore, the display surrounded by a frame in the figure means inversion of black and white, and this is controlled by the attribute beat information stored in the display RAM areas of the RA and M2S. In the display of FIG. 3, the bar-shaped display consisting of the diagonal line and the white part in the upper right corner has a horizontal length that is equal to the entire stored logic signal under test (the entire second and third area signals of the RAM 28 and the displayed bar-shaped display). The relationship can be determined.This bar-shaped display
Displayed by the method disclosed in No. 24579.
:,.

The "C" displayed in the center of the display in FIG. 3 and seven black squares in the vertical direction indicate the cursor, and the keyboard 30
Its position is controlled by That is, when the address of the cursor position corresponding to the displayed waveform is determined by the keyboard 30, the two CPUs move the cursor to the corresponding address in the display RAM area of the RAM 28 and change the font and attributes based on the cursor position information. 1. Memorize information. Therefore, when the display control circuit 32 repeatedly reads out the display RAM area, a cursor is displayed on the CRT 34. Further, the "l'-1e] 1001" lined up vertically on the right side of the display in FIG. 3 is effective for confirming the cursor word when the interval between the rising and falling edges of the cursor is narrow. The display of this cursor word is performed by the CPU 24 in the following order based on the firmware in the RAM 28. First, the CPU 24 successively generates data at the cursor position from the data information stored in the second area of the RAM 28 based on the cursor position information stored in the first area of the RAM 28 . The CPU 24 reads “1” and “0” of this read data.
'', font information corresponding to each character (1, θ) is stored in the display RAM area of the RAM 28, and displayed on the CRT 34 in the same way as other displays.

When the saw crane is moved using the keyboard 30, the RA
The cursor position information in the first area of M28 changes and becomes -1
-Repeat the above operations. Further, even after the cursor position has moved to both ends of the displayed waveform, the cursor has been moved on the keyboard 30 so as to move the cursor further to the outside of the displayed waveform. For example, if you command the cursor to move to the right after the cursor has moved to the right edge of the displayed waveform, the displayed waveform will move to the left, and the waveform corresponding to the amount of the cursor movement will disappear from the left edge of the display. A new waveform for minutes appears from the right edge. At this time, the white part of the bar-shaped information indicating the display area moves. Such operation is generally referred to as scroll mode. In the scroll mode (13), the display area is determined by the cursor, and the CPU 24 may newly read logic signals for the entire display area from the second and third areas of the RAM 28, and repeat the above-described display operation. However, only the address of the bone to which the cursor is moved is displayed by the CPU 24 in the RAM 28.
The CPU 24 shifts the waveform information of the area, reads out the missing waveform information due to this shift (the shifted amount is deleted from the waveform information in the shift direction) from the second and third areas of the RAM 28, and newly displays the waveform information in the RAM 28. Clarify the area.

When the search mode is selected using the keyboard 30, the CP
U24 uses the firmware in ROM26 to display RA
I 5RCHj (5e
simplification of arch means search). If the phenomenon to be searched is a word, 1'-8RCI (under J
WD J (word simplification) is also displayed.

Next, a word to be searched, ie, a search word, is input manually from the keyboard 30 via the bus 20 and (14) CPU 24, and is stored in the first area of the RAM 28. In this example, this search word is []011
eOeJ, is converted into character information (font and attribute information) by the CPU 24, and is stored in the display RAM.
The data is stored in the area and displayed as shown in FIG. CPU24
compares the search word stored in the first area of the RAM 28 with the data information stored in the second area, counts the total number of search words in the second area, and stores the result in the RAM 28.
28 in the first area. In this example, the total number>!
There are 200 characters, which are converted into character information by the CPU 24 and stored in the display RA and M areas, and then stored in the CRT.
34 is displayed as r2oeJ. Also, the CPU 24 is RA
Based on the cursor position information in the first area of M28,
The number of search words contained in the second area before the address of the cursor position is counted. In the example of FIG. 3, there are 113 search words before the cursor and a 114th search word after the cursor. In this case, the CPU 24 stores character information corresponding to "←113" in the display RAM area to display that there is the 113th search word before the cursor. The cursor is sequentially moved to the right using the keyboard 30, and when the cursor position corresponds to the 114th search word, CR
At T34, a display as shown in FIG. 4 is made. That is, rsR
From the display cH=114/2e(II)J, it can be seen that the cursor position is the 114th out of 200 search words. The arrow disappears from the display when CPU2
4 counts the search words up to the cursor position,
The cursor position is the cursor stored in the display RAM area.
Changes the word character information attribute and inverts the cursor/word display. These search functions are R
It is controlled by the OM26 firmware.
・Therefore, it is possible to search for logic signals stored in the storage means.
The relationship between the total number of words and the cursor position is obtained, making the measurement of logic signals very convenient.

A search function can also be applied in timing display mode, making measurements even more convenient. For example, if the search word is after the cursor position (on the right side), rsRcH
--113/2[)J may be displayed. If the search word is indicated by an arrow (and the cursor word is not a search word), it is indicated by a "←" arrow when the cursor is moving to the right, and by a "←" arrow when the cursor is moving to the left. When the time is displayed with a “-” arrow,
If the cursor movement is automatically stopped when the cursor reaches the position, the search word can be searched automatically (automatic search mode). In order to perform this automatic search mode, the counter sequentially updates the cursor position information in the first area of the RAM 28 by counting low-frequency clock pulses, and the CPU 24 determines whether the cursor word and the search word match. It is sufficient if the counter stops counting when this happens (17). Furthermore, when it is desired to search for the next search word, the counting operation of the counter can be restarted.

FIG. 5 is an example of a display on the CRT 34 when the phenomenon to be searched for in the timing display mode is a glitch. In this display, the thick black line within the waveform is a glitch, and this glitch is displayed by converting the glitch information in the $3 area of the RAM 28 into attribute information by the CPU 24 and storing it in the display RAM area. The keyboard 30 is stored and displayed on the CRT 34. search·
Similar to the word search, the CPU 24 counts the total number of glitches stored in the third area of the RAM 28, also counts the number of glitches before the cursor position, and stores these values as character information in the display RAM area. and display it on the CRT34. In the case of glitch search, even if glitches exist in multiple channels with the same corresponding address (even if multiple glitches exist on the same time axis (18) in the display), they will be counted as one glitch. do. In the case of Figure 5, the total number of glitches is 189, and the glitches at the cursor position (channels A4 and A
7) is 13535th.

The operation of the CPU 24 is almost the same as in the case of search words, but among the cursor words at the far right of the display, only the data of the channel containing the glitch is inverted (black and white).
The points (encircled by a frame) are different. However, all Taeyang Lee
CRT when the phenomenon of reversing the black and white data of the file is word
34 is a display example. The difference from the operation described with reference to FIGS. 3 and 4 is that logic signals are represented only by the letters "l" and [J. Therefore, the data in the display area specified by the keyboard 30 is converted into character information by the CPU 24 and stored in the display I<AM area. In addition, in the display of FIG. 6, AO to A7 in the third line
represents each channel number, and the display below these numbers is the data of each channel. [,1゜2...11,1.2J, which are arranged vertically on the left side of the display, are RAM2
This is the address number of the second area of 8. These channel numbers and address numbers are displayed by the firmware in the ROM 26. The three horizontal bars displayed at address number “8” are cursors controlled by the keyboard 30. Therefore, the display [5RCH-12/20LJ
The total number of search words is 200, which is the same as in the second mode before the cursor position at address 8 (on the other hand). If the display is "rsRcH-↓ 3/20θ", there is a third search after the cursor position (downward).
It shows that there is a word. Since the data at addresses 2 and 5 are search words, black and white are inverted.

This means that when the CPU 24 compares the data in the second area of the RAM 28 with the search word, it finds a matching address.
This is done by controlling the attributes of character information corresponding to one space.

FIG. 7 shows an example of a display on the CRT 34 in the state display mode when the phenomenon to be searched for is a glitch. The operation related to the search mode is almost the same as the operation related to FIG. 5, and the operation related to the state display is almost the same as the operation related to FIG. 6, so a detailed explanation will be omitted. 7th
The display in the figure shows that the total number of glitches is 124, and the cursor position at address 104 is the 73rd glitch.
It is effective to invert data containing glitches since the black and white inverted data does not display glitches. All data of an address including a glitch may be displayed in reverse black and white.

FIG. 8 shows another display example of the CRT 34 in the state display mode when the phenomenon to be searched for is a glitch. This display is almost the same as FIG. 7 except that the data is displayed in hexadecimal notation. Based on the firmware in the ROM 26, the CPU 24 divides the data (21) stored in the second area of the RAM 28 into channels of 0.1, 2.3, and 4.5°6.7.
It is divided into two sets of Tejannels and converted to hexadecimal. "■" on the third line of the display is in hexadecimal notation.
l) Indicates that it is a display.

As mentioned above, according to the logic analyzer of the present invention,
Since the relationship between the total number of predetermined phenomena (search words, glitches) included in the input logic signals stored in the storage means and the cursor position on the display means can be obtained, the search function can be used effectively. Additionally, a search function can be used even in timing display mode, making measurements even more convenient.

Although only the preferred embodiments of the present invention have been described, those skilled in the art will understand that various modifications and changes can be made without departing from the spirit of the present invention. For example, the third
The automatic search function and scrolling mode described in connection with FIGS. 4 and 4 can also be utilized in the operations of FIGS. Furthermore, when a predetermined phenomenon is detected, display control methods such as brightness modulation and underlining can be used in addition to black and white inversion.

(22)

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a preferred embodiment of the logic analyzer of the present invention, FIG. 2 is a diagram showing the storage contents of the storage means 28 of FIG. 1, and FIGS. 3 to 8 are representations of FIG. 1. Means 34
FIG. 24: Processing means 28: Storage means 30: Input and cursor control means 34: Display means Patent applicant 2 Sony Tektronix Corporation (23)

Claims (1)

[Claims] The input logic signal is stored in the storage means, and the logic signal stored in the storage means is displayed on the display means (-). processing means for counting the total number of the phenomena from the generated logic signal, and cursor control means for controlling the cursor position of the display means,
A logic analyzer characterized in that the processing means determines the relationship between the total number and the cursor position.