KR100193589B1 - Test Methods for Microcontrollers - Google Patents

Abstract

A test method for a microcontroller that selects a test mode by reading an external command including a test-mode switching register, the test method including an external mode, an internal mode, and a read application. By the three methods described above, the item function under test is tested for normal operation to improve the test efficiency of the microcontroller.

Description

Test Method for Microcontroller

1 is a block diagram showing a conventional test method for an integrated circuit (IC).

2 is a block diagram illustrating another conventional test method for an IC.

3 is a block diagram illustrating one embodiment of a test system in accordance with the present invention.

4 is a flowchart of test steps according to the invention.

* Explanation of symbols for main parts of the drawings

10: test machine 12: items to be tested

28: test machine II 30: control circuit-I

32: Multiplexer 34: Application Memory

36: test program memory 38: test control circuit

40: ROM readout device

42: test mode switching register

[Background of invention]

[Field of Invention]

The present invention relates to a test method for an integrated circuit (IC), and more particularly to a test method for a microcontroller. The method includes three channels, an external mode, an internal mode and a reading application program mode, to improve the test efficiency of the microcontroller.

[Explanation of Conventional Technology]

As IC products are widely used in everyday life items to advanced technology items, and IC quality is closely related to product functions, the IC function testing method plays an important role.

Conventional IC test methods are divided into two types. 1 is a block diagram showing a conventional IC test method, wherein the test machine 10 in the block diagram transmits a control signal to an item 12 to be tested to perform a test, and the next tested item 12 is The signal is transmitted to the test machine 10 and compared with the desired value to determine whether the item under test has a normal function. The test machine 10 simulates the actual operation of the item 12 being tested. If the item 12 to be tested has more functions to be tested, the test item installed in the test machine 10 should be further increased, thus extending the overall testing time and eventually increasing the cost.

When the test is performed on a microcontroller, the functions of the components of the microcontroller are controlled by an internal program due to the elements including built-in program units and a state machine. In other words, different program operations have different outputs. When the conventional test method as shown in FIG. 1 is used, it becomes difficult to test because the test item and the test mode have to be changed as soon as the built-in program of the microcontroller is changed.

Regarding microcontroller testing, some manufacturers have developed a test problem, which means that the test machine sends various commands to the microcontroller to perform the test, and then returns the results of the microcontroller's performance to the test machine. To send and compare. However, using the method described above, the timing must be separated to facilitate two signal transmissions, in which case not only is time wasted but the timing is different from real timing. Often, the test results are all accurate, but the device's actual function can be disrupted and affect IC quality.

FIG. 2 is a block diagram illustrating another conventional test method for an IC, in which the item under test 12 includes a control circuit 18 to decode the command to perform this command and then signal the test machine-I. (14). The original control signal source (24) is used to store the application program. The control signal generator 22 is used to store the test program to perform a self-test, and the test program If the program memory is switched to the test program during the test, the control signal generator 22 causes the item under test to self-test according to the built-in test program, and the test result signal is It is transmitted to the test machine-I via the control circuit 18 and compared with a default value to detect whether the item function under test is normal.In the above-described test method, the built-in test of the control signal generator 22 The program is difficult to change after it's designed, ie low test flexibility. In order to reduce most of the program memory space is used for storing the application, the remaining space is used for storing the test program, in this case, the test items are poorly it affects the quality of the item.

According to the above description, the conventional test method for the microcontroller has some drawbacks, which must be improved.

[Summary of invention]

The primary object of the invention is to provide a test method for a microcontroller, which includes an outer mode, an inner mode and a reading application program mode, i.e. three The channel is used to send commands to perform tests, which shortens test time and prevents incomplete tests that affect IC quality. To test different ICs to see if these IC functions are normal, the microcontroller test method is designed to have multiple channels and functions, allowing the user to choose the appropriate one. Depending on the functionality to be tested, the inventors can design different functional items, ie additional test items can be provided in the space available to the user.

[details]

In order for the examiner to fully understand the object, features and functions of the present invention, the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 3, the item under test 12 according to the present invention includes a test mode switching register 42 and a test control circuit 38, which is classified as an external mode. The test mode switching register 42 receives an external command from a test instrument such as test machine-II 28 to select a test mode. That is, this register can switch to each of the various test modes, and test modes can be added if necessary. The test control circuit 38 is used to control the timing of the foreign command sent from the test instrument; This external command is also sent to the control circuit-I 30 via the multiplexer 32; Control circuit-I 30 decodes the instructions to execute program instructions and transmits the signals to a test instrument such as test machine-II 28 for comparison.

The microcontroller's original memory is divided into two parts, the application memory and the test program memory, which is classified as internal mode. Application memory 34 is used to store application programs; The test program memory 36 is used to store the test program. During the test, the memory of the microcontroller is switched to the test program memory 36 to perform self-test by the built-in test program. The test program is designed in a modular type, that is, based on a single set of test functions to provide flexible test functions. The ROM reading device 40 is used to read the program code from the program memory 34 to test whether the application program memory 34 is properly read so that the stored application program can be executed. The present invention can perform the test by three channels; If the internal mode does not provide enough test functionality or is useless, the external mode is used instead to overcome the incomplete test problem; Thus, the method according to the invention not only improves test efficiency but also increases the range of test items.

4 is a flowchart of a test embodiment according to the present invention; The first step is to turn on the power (44); The next step is to determine if the test is performed (46); If the answer is NO, then the item under test enters into the normal execution of the program (48); If the response is YES, the signal is sent to the test mode switching register to execute the external mode 50; The switching register then reads external command f to select test mode 52. When the external mode 50 is selected, the control circuit in this mode transmits a signal. When the test is complete, the signal returns to the test-mode switching register of external mode 50. When the internal mode 58 is selected, the signal enters the test program memory of the internal mode 58 to select a test function. After the test is completed, the signal is returned to the test mode switching register of the external mode 50.

Once all test functions are completed via external mode 50 and internal mode 58, read application mode 54 is used to execute the command, and then the test ends 56.

However, the above description is only described for the preferred embodiment according to the present invention, and should not be construed to be limited thereto; It should be understood that any change or modification to the claims of the present invention shall fall within the claims of the present invention.

Claims (6)

A test method for a microcontroller which performs different testing modes to transmit a test result of an item under test to a test apparatus, wherein the test mode transmits an external command to the item to be tested by the test apparatus to the item. An external mode for selecting various test modes with respect to the external device, an internal mode for receiving a selection by an external command from the test device to execute a self-test by a built-in test program in which the item to be tested is stored, and the test device A readout application mode for receiving a selection by an external command from the application and reading the program code of the application stored in the item under test and causing the test instrument to compare. How to host. The method according to claim 1, wherein the test steps include: ① determining whether the test is performed, that is, whether the test item can be normally executed when the test is performed; Reading an external command from the test instrument in an external mode to select and perform a test of the external mode, or selecting another test mode; and (3) when the external mode is selected, the item under test is the test instrument Decoding the external command from the computer to execute the command and sending a test result back to the test apparatus; and ④ after all the test functions are completed, the test command sends an external command to switch the test mode to the reading application. Step to run the test, and ⑤ test Test method for a microcontroller comprising a charge phase. The microcontroller according to claim 2, wherein the test step (3) is selected in order to perform a test when the internal mode test is selected without preceding the external mode test, and a test result is transmitted to the micro controller. About the testing method. The test method of claim 3, wherein when the internal mode is selected, a built-in program of the tested item includes at least one test function. The method of claim 2, wherein the test step ③ is not selected, but instead, the test step ④ sends an external command to the test apparatus to switch the test mode to the read application mode to perform a test. Testing method. The test mode switching register of claim 1, wherein the item to be tested is electrically connected to a test mode switching register configured to receive an external command from the test apparatus, select a test mode, and switch to various test modes as required. And a multiplexer for controlling the timing of an external command from the test mechanism and transmitting the external command, a multiplexer electrically connected to the test control circuit to receive an output signal of the test control signal, and the mulpyplexer. A control circuit that receives an output signal that is electrically connected, decoded and executed, and transmits an execution result to the task instrument; and an internal test program that is electrically connected to the multiplexer to store an internal test program, and that the internal mode outputs an output signal when performing the test. Above multi A test program memory to be transmitted to a lexer, an application memory used to store an application program and to transmit program code in accordance with the read application mode, and to be electrically connected to the multiplexer to read a program code of the application memory. And a ROM readout device to facilitate the comparison by the test instrument.