JPH0430228A - Information processor - Google Patents

Abstract

PURPOSE:To observe the state of an arbitrary flip flop by permitting a logical unit including a register being the object of scan to select a scan address from a scan control part and to execute a scan operation in the middle of the scan operation. CONSTITUTION:When the scan operation is executed, a scan busty signal 5 becomes '1' and the scan address of a scan address register 2 is inputted to a scan address decoder 7. As the decoding result of the scan address, a scan enable signal 9 becomes '1' and the output of a scan address selector 15 is switched from the output of a scoping scan address register 13 to the scan address which a scan control part 1 outputs, for example. Then, the scan-out operation is executed as against a flip flop group 33 and the content of the flip flop group 33 is set to a scan out data register 3 through a scan out data path 24. Thus, the state of the arbitrary flip flop can be observed even at the time of the scan operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an information processing device, and particularly to an information processing device that is easy to maintain and adjust.

[Prior Art] A flip-flop in an information processing device has the function of holding the results of logical processing by a combinational circuit and also defining input conditions for the combinational circuit. This is important information to understand the operation.

Therefore, during logical adjustment and maintenance work,
Observing the state of flip-flops is essential for confirming normal operation, investigating the cause of malfunction, pointing out faulty parts, etc.

As described in Japanese Unexamined Patent Publication No. 55-92953, the conventional device is equipped with a maintenance scan address register independent of the scan control section used for normal scan-out operation, and the maintenance scan address register is We are observing the specified flip-flop.

FIG. 2 shows a block diagram of such an information processing device. A scan control section 1 is installed attached to the information processing device. The scan control section 1 includes a scan address register 2 and a scan-out data register 3. Scan-out operation is performed using scan address register 2.
is activated after specifying a specific flip-flop group 32.

When the scan control unit 1 is activated, the scan busy signal 5 becomes "1", and the scan address selector 30 supplies the contents of the scan address register 2 to the scan address decoder 7 via the scan address bus 6. This decoder 7 enables the scan-out bit selector 16 and the like by generating scan enable signals 8 and 9 for the LSI (or board) 10.11 designated by the scan address. At the same time, the contents of scan bit counter 4 are passed to scan address bus 31 to scan out bit selector 1.
6, the scan bit counter 4 starts counting up.

Due to the count up of scan bit counter 4,
The states of the flip-flop group 32 are sequentially selected from the scan-out bit selector 16 to the scan-out path 24, and are sequentially set in the corresponding bits of the scan-out register 3.

Scanning out of the flip-flop group 32 is performed as described above.

During scan non-operation, scan busy signal 5 is “
In this case, the scan address selector 30 outputs the contents of the maintenance/scan address register 9 to the scan address bus 31. As a result, the scan address decoder 7 and the scan-out/focus selector 16 operate, and the output of the flip-flop 18 designated by the maintenance/scan address register 9 is output to the scan-out path 24.

An observation device 27 is connected to the scanout path 24 . Therefore, it is possible to observe changes in the state signal of a particular flip-flop 18 during scan non-operation.

Problems to be Solved by the Invention C] The above-mentioned conventional technology does not take into consideration observation during scanning operation. That is, since the scan-out path is shared with the observation path and the maintenance/scan address register is selected only when the scan control section is not operating, there is a problem in that it is not possible to observe the operation of the flip-flop during the scan operation.

The present invention aims at observing the operation of an arbitrary flip-flop during a scan operation, and further aims at making it possible to observe the operation of a plurality of flip-flops simultaneously.

[Means for Solving the Problems] In order to achieve the above object, an information processing device according to the present invention specifies an arbitrary flip-flop group among a plurality of internal flip-flop groups, and specifies the contents of the flip-flop group. In an information processing device having a scan control unit that scans out and retrieves data by updating a scan address,
An address register that holds an address specifying an arbitrary flip-flop in a group of flip-flops to be scanned, and a bit selector that selects and outputs the state of the specified flip-flop according to the output address of the address register. , a first output terminal that outputs a bit output of the bit selector; a selector that provides the scan address to the bit selector instead of the output address of the address register when receiving a designation from the scan control section; A second output terminal for outputting a bit output of the bit selector upon receiving a designation from a scan control section is provided for each flip-flop group to be scanned.

Address register (hereinafter referred to as scoping/scan address register) that holds an address that specifies any flip-flop that constitutes the scan target register.
A plurality of them are distributed and installed in the information processing device. Each scoping data path outputting the state of the flip-flop specified by the scoping scan address register is connected to an observation device.

While the scan is not in operation, the operating state of the flip-flop specified by each scoping/scan address register is output to the observation device.

During a scan operation, the scan operation is performed for the logical unit that includes the register targeted for scanning by selecting the scan address from the scan control unit, but for other logical units, scanning is performed using the scoping scan address register. The address remains selected and the state observation of the specified flip-flop continues.

In this way, the state of any flip-flop can be observed even during the scan operation. Furthermore, each logical unit is provided with a plurality of scoping/scan address registers, and by switching them, it is possible to easily change the flip-flop to be observed.

[Example 1] An example of the present invention will be described below with reference to FIG. In this figure, elements that are the same as those shown in FIG. 2 are given the same reference numerals.

As shown in FIG. 1, the present invention installs a plurality of scoping/scan address registers 12 and 13 in which scan addresses can be set in a distributed manner within an information processing device, and uses the registers 12 and 13 to set scan addresses. The configuration is such that the contents of this scoping/scan address register 12.13 are selected by a scan address selector 14.15.

Furthermore, the bit selector 16 when a scan address is selected by the scan address selector 12.13
．． Output terminal 36.37 (
In addition to the scanout data path 24 connected to the second output terminal (second output terminal), an output terminal 34 outputs the bit output of the bit selector 16-17 when the scoping scan address register 12-13 is selected. .35
Observation scoping data paths 25 and 26 are provided, respectively connected to (first output terminals). By setting the scan address of the flip-flop that requires observation in the scoping scan address register 12.13, the scoping data path 25.26
The state signal of any logical signal output from the observation device 2
It is input at 7°28.

The scan address set in the scoping scan address register 12-13 will not change until it is reset, so the contents held in the flip-flop indicated by that address will be used as the scoping data.
It is output from paths 25 and 26, and the change in the state of the flip-flop over time is observed.

When the scan is not in operation, the scan busy signal 5 is "O", so the scan enable signals 8 and 9 become rOJ, and the scan address selector 14.15 scans out according to the contents of the scoping/scan address register 12.13. - Operate bit selectors 16 and 17. Scoping・
A particular flip-flop 18.19, each designated by a scan address register 12.13, is output by a scoping data path 25.26 and observed by a wA measuring device 27.28.

When a scan operation is performed, the scan busy signal 5 becomes "1" and the scan address of the scan address register 2 is input to the scan address decoder 7. As a result of decoding the scan address, for example, the scan enable signal 9 becomes "1", and the output of the scan address selector 15 is switched from the output of the scoving scan address register 13 to the scan address output by the scan control unit 1. A scanout operation is performed on flip-flop group 33 and the contents of flip-flop group 33 are set in scanout data register 3 through scanout data path 24 .

On the other hand, even during the scan-out operation of the flip-flop group 33, the scan enable signal 8 remains "O", so the scan address selector 14 is not switched and the output of the scoping/scan address register 12 continues to be selected. Therefore, the output of the flip-flop 18 continues to be outputted from the scoping data path 25 regardless of the scan operation, and it is possible to continuously observe state changes.

In the above embodiment, only one scoping/scan address register 12 is provided in each LSI, but a plurality of registers may be provided so that switching between them may be possible. This makes it possible to observe the contents of different flip-flops simply by switching the registers without resetting the contents of the registers.

According to this embodiment, by installing a plurality of scoving/scan address registers and providing an observation path independent of a scan-out path, the state of any flip-flop other than the scan operation is executed. It has become possible to observe continuously regardless of the situation, and it has also become possible to observe multiple flip-flops at the same time.

This has the effect of improving efficiency during maintenance and adjustment.

[Effects of the Invention] According to the present invention, it is possible to observe the state of any flip-flop not only during non-scan operation but also during scan operation. Further, by installing a plurality of scoping/scan address registers in the information processing device, it becomes possible to simultaneously observe the states of a large number of flip-flops.

These improve efficiency during maintenance and adjustment.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an information processing apparatus equipped with a flip-flop state observation function showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional flip-flop state observation method of an information processing apparatus. scan control unit, 2...scan address register,
3...Scan out data register, 4. Scan bit counter, 5. Scan busy signal, 6.3
1. Scan address path, 7. Scan address decoder, 8, 9. Scan enable signal, 10.
11. LSI or board, 12.13. Scoping scan address register, 14.15. Scan address selector, 16.17. Scan out bit selector, 18.19. Flip-flop, 20
゜21.22, 23...Combination circuit, 24...Scanout data path, 25.26...Scoping data path, 27.28...R measurement device, 29
・・Maintenance scan address register, 30
Scan address selector, 32.33 Flip-flop group. 1 person Hitachi, Ltd.

Claims (1)

[Claims] 1. A scan control unit that specifies an arbitrary flip-flop group among a plurality of flip-flop groups inside an information processing device, and scans out and retrieves the contents of the flip-flop group by updating a scan address. An information processing device having an address register that holds an address specifying an arbitrary flip-flop in a group of flip-flops to be scanned, and a state of the specified flip-flop selected according to an output address of the address register. a bit selector for output; a first output terminal for outputting a bit output of the bit selector; and a first output terminal for outputting a bit output of the bit selector; and a second output terminal that outputs a bit output of the bit selector when receiving a designation from the scan control unit for each flip-flop group to be scanned. Information processing device.