KR0149258B1 - The test circuit of multi-functional micro-controller - Google Patents

Abstract

1. the technical field to which the invention described in the claims belongs; A test circuit for a multifunction microcontroller.

2. The technical problem to be solved by the invention; The present invention provides a test circuit of a multifunctional microcontroller for performing a complete test operation.

3. Summary of the Solution of the Invention; The test circuit of the microcontroller for performing the multifunction includes: first and second ports for receiving a test command; A programmable pathsector for selecting a path of signal lines between the first and second ports and the first and second modules; It is essential to have a test register for causing the signal line of the path sector corresponding to the port to be electrically disconnected.

4. Significant use of the invention; It is suitable for the test circuit of the multifunctional microcontroller to perform a complete test operation.

Description

Test circuit of the multifunction microcontroller

1 is a view showing the connection of each port and each module of the multi-function microcontroller according to the prior art.

2 is a block diagram showing a test circuit of the multifunctional microcontroller according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test circuit of a multifunction microcontroller in a semiconductor memory device, and more particularly to a test circuit of a microcontroller for performing multifunction with a small number of pins.

In general, products of conventional microcontrollers have one or several ports for testing, and commands are issued through the ports described above. Therefore, due to this test method, it was difficult to test the port to insert the command. Therefore, the design to have a specific function through the command port has been avoided as much as possible.

However, modern microcontrollers tend not only to have many built-in features but also to have fewer pins. For this reason, it is a trend to connect the input terminal and the output terminal of the module having a special function to the port for inserting a command during the test. 1 shows a connection relationship between each port and each module of the conventional multifunction microcontroller. Referring to FIG. 1, the first module 40 and the first port 10 are connected by input / output signal lines e1-e8, and the second module 50 and the second port 20 are input / output. It is shown connected by the signal lines f1-f8. However, in this connection state, if the first port 10 is a port for inserting a command, the test of the first module 40 becomes very difficult. Thus, due to the recent technical trend as described above, it can be seen that the test operation of the microcontrollers becomes more difficult. In other words, it is difficult to test a module that is connected to the port as well as the port receiving the command by a method of performing a test by applying an external command.

Therefore, in order to solve the difficulty of the test due to the connection structure as shown in FIG. 1, there is a test performed using the internal test program memory as one of the other known test methods. However, this also defines a test vector representing the testable range depending on the size of the test program memory. For this reason, a complete test may not be possible, and the vector generation is difficult because the test vector is complicated. In addition, the test vector, once made, is difficult to modify, and if a modification is required, a problem arises that is time-consuming and expensive.

Accordingly, it is an object of the present invention to provide a test circuit of a multifunctional microcontroller capable of performing an improved test operation.

According to the present invention for achieving the above object, it is possible to perform a test on a module connected to the ports for receiving a test command, the test circuit of the microcontroller for performing multifunction with a limited number of pins, the test command Receiving first and second ports; It is controlled in response to an activation signal applied, and is connected to signal lines of the first and second ports and to signal lines of the first and second modules, so that the test for the module is performed. And a programmable path sector for selecting a path of signal lines between the first and second modules; When a test of a module connected to a port into which the test command is input is performed, a signal register of the path sector corresponding to the port is electrically disconnected, and a test register outputting the activation signal for controlling the path sector. It is characterized by having.

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

2 is a block diagram showing a test circuit of the multifunction microcontroller according to the present invention.

Referring to FIG. 2, signal lines a1-a8, b1-b8, c1-c8, and d1-d8 are connected between the first and second ports 10 and 20 and the first and second modules 40 and 50. It is shown that the path sector 30 is connected between the signal lines a1-a8 and b1-b8 and the signal lines c1-c8 and d1-d8. The operation is controlled in response to the activation signal set to which the pathsector 30 is applied, and the first, second (10, 20) and the first to make the test for the modules 40 and 50 are performed. It is programmable to perform the function of selecting a path of signal lines between the two modules 40 and 50.

When the test of the module connected to the port to which the test command is input is performed, the test register 60 allows the signal line of the path sector corresponding to the port to be electrically cut off and controls the path sector 30. The activation signal set is output. Here, even when the set signal is not activated, d1 and b1 are connected by the path sector 30, and in turn, d2 and b2, d3 and b3,... Since, d8 and b8 are connected, the test for the second module 50 can be performed without any problem.

Meanwhile, when the first module 40 is to be tested, the signal lines of the first module 40 and the second port 20 are connected to each other by the path sector 30. That is, when the set signal, which is one bit of the test resist 60, is activated, the signals c1 and b1, c2 and b2, c3 and b3, ..., c8 and the first module 40 and the second port 20 are activated. b8 is connected to each other. In this case, the signal lines a1-a8 between the first port 10 and the path sector 30 are electrically disconnected. Here, the signals connecting the second port 20 and the pass sector 30 are bidirectional. The reason for this is as follows. When the second module 50 is tested, the b3 signal line is connected to the d3 signal line to be output to the outside, and the b3 signal line when the first module 40 is tested is connected to the c3 signal line to receive an external input. It is a signal. That is, the signal line between the second port 20 and the pass sector 30 has bidirectionality because the direction of the signal line may change when the first module 40 is tested and when the second module 50 is tested. It is.

According to the present invention as described above, the multi-function microcontroller has the advantage of providing a rewritten test operation even with a small number of pins.

Claims (1)

A test circuit of a microcontroller capable of performing a test on a module connected to ports for receiving a test command, wherein the test circuit of the microcontroller for performing a multifunction with a limited number of pins, comprising: first and second ports for receiving the test command; It is controlled in response to an activation signal applied, and is connected to signal lines of the first and second ports and to signal lines of the first and second modules, so that the test for the module is performed. And a programmable path sector for selecting a path of signal lines between the first and second modules; When a test of a module connected to a port into which the test command is input is performed, a signal register of the path sector corresponding to the port is electrically disconnected, and a test register outputting the activation signal for controlling the path sector. It has a test circuit characterized by the above-mentioned.